Via email from Chris M. we have an example of how difficult complete privacy is:

Surveillance Via Smart Toothbrush – Schneier on Security

a marital affair was discovered because the cheater was recorded using his smart toothbrush at home when he was supposed to be at work.

Private investigator reveals how a TOOTHBRUSH can prove if your partner is cheating | Daily Mail Online

Paul worked with a client who became suspicious of her husband after noticing unusual times he’d brush his teeth. She had installed a smart electric toothbrush app to help encourage their kids to brush properly but the app also tracked every session for the whole family.

“Over time, the client noticed their partner’s brushing history was being logged at odd times, times when they were supposedly at work,” Paul explained. At first, it didn’t seem like much, brushing late in the morning on Fridays didn’t raise immediate red flags.

“And in that time he had started an affair with a work colleague and used to have her over the family home on a Friday when the wife and kids were out of the house,” he added.

I no longer work in the Cyber Threat Intelligence group at work, but when I was on the team our analysists would sometimes track down bad guys over the course of months of collecting “breadcrumbs”. The bad guys would post things that in of themselves were essentially useless. But cumulatively they added up to positive identification and location of perpetrators who had defraud the company and/or our customers of millions and some cases of tens of millions of dollars.

One example I participated in was as follows. The analysts noticed large numbers of nearly identical messages would be posted on multiple Telegraph channels by a criminal claiming ability to defraud our company and his willingness, for a price, to teach others how to do the same thing. I wrote a program that would find all the users names associated with publishing these nearly identical messages. It turned out that occasionally the same message would be posted by two different users names within a few seconds of each other in different channels. One user would post the message in one or two channels. The other user would post it in 20 channels. The one channel posting username would “drop off the radar” at the same time as the new username posting in 20 channels appeared. It was, almost for certain, the same person changing their username over time.

Hence, we could track the same person over a year or more even though he changed his username every few weeks. This allowed us to find a lot more breadcrumbs to narrow the search.

These perps would drop social hints such they were at a party, but they had to leave soon because it was 2:00 AM. By comparing the stated time to the UTC timestamp in the channel, we could determine the time zone they are in. They would post a picture holding something in their hand proving they had defrauded the company. Now we know their skin color and perhaps the color of their watch. When searching social media posts for information about the party we could use the skin and watch color to tie the fraudster username to a social media account. If the electronic object they posted had a clock on it and it is outside, from the shadows we can get an approximation of the latitude they were at. If they would post the social handle of their girlfriend, now we have more breadcrumbs to collect. The girlfriend would post a picture of a scenic site. Now we can do reverse images searches to find that landscape or better yet, a famous building. Now we have their residence or vacation location within a few dozen miles. Or that identical picture would show up in a social media account. Bingo!

The smallest things add up.

People have concerns about electronics in their homes and vehicles spying on them. Yes, this is a concern. These things can be firehoses of information and the smallest things add up.

But keep in mind that it is possible to create an Internet of Things (IoT) enabled house without leaking information to everyone. It is more work than using Amazon’s Alexia or Google Nest, and you probably have to be a geek of some sort to push through some of the issues. * But you can completely isolate a “Smart Home” from the Internet and still use it for monitoring and controlling your home. You would have to be home to access the data or change the programming, but you can do some amazing things. Or you can pay a few dollars a month and access it via https (encrypted) connections from anywhere you have Internet service.

Because I am away from my underground bunker most of the time, at least for now, I chose to pay a few dollars to access it remotely.

I have hundreds of sensors in my underground bunker. Walking through you probably would only see dozen or so at most. But that thermometer also has a humidity sensor in it. That makes twice as many sensors as you first thought and the measurements they report give you more information than you might guess. I could tell what room a contractor was working in because the humidity and temperature would rise if they spent more than a few minutes in a room. When a contractor would paint, then the humidity would go way up. I set up leak alarms (the alert would be on my phone, not in the room) based on high humidity and once the painting done by the contractor set off the leak detection logic.

For people who can’t imagine why they would want their house instrumented, I know two homes that were severely damaged due to leaks. One summer home was completely destroyed because it sat for months with the basement overflowing with water. Brother Doug’s home had the tubing to the toilet rust out and spew water for several hours in an upstairs bathroom. That destroyed drywall on the main floor and basement and flooring on the upstairs floor and main floor. A few years later a second flood was caused by squirrels nesting in the drain leading water from around the basement. A heavy rainstorm put about two inches of water in the basement and even though Brother Doug was in the house he did not notice for over a day because he did not go into the basement. With leak sensors and/or high humidity alarms he and his wife would have saved thousands of dollars and many hours of time.

I use temperature sensors to optimize the use of a geothermal heat pump, the buffer tank, the hybrid water heater, and secondary electrical resistance heating in my underground bunker. With remote access, the outside door light can automatically be turned on when you are driving home in the dark and get within 100 yards of the door. That probably isn’t that much interest to city dwellers, but when there are no streetlights, a little extra light getting into the house can be quite welcome. Motion sensors and door opening sensors can be used to detect someone moving around in your home when you are not there and send an alert to your phone.

If you don’t mind being spied on by your appliances** you could get alerts if you left a refrigerator or freezer door open. You can get an alert the drier has completed its job, and you should get your clothes out before they wrinkle, and you get notified with it is time for the water filter in youf refrigerator to be changed. You don’t remember if you turned off the oven and you are a block away from your house on the way to work? The app for your oven can tell you whether you need to return home or continue to work without worrying about it. You can open the garage door remotely and watch on a webcam as FedEx delivers a large package. And/or you could get an alert if someone else opened the door when you did not expect it.

Barb is pretty vehement about not wanting her house to spy on her. But after Brother Doug’s second house flood, she put something like ten leak sensors in various places around her house.

Depending on which leak sensor gets wet, my underground bunker computer will do more than just fire an alert. If appropriate, it will turn off the water supply, the water heater, and the water conditioner.

Operated by five-year batteries, leak sensors can be discretely placed in out of the way places and provide peace of mind without significant information being leaked. There is a remaining battery life sensor and a binary “wet”/”dry” sensor. Even if they were hacked or the manufacturer collected usage data, what do you care about that information being obtained by others?

The underground bunker is more fire resistant than most homes. But I can remotely turn on outdoor sprinklers to protect the backup generator, electrical meter, well, bunker doors, and windows. Short of deliberate human acts, the bunker exterior complex should be fireproof.

Yes, the smallest details can add up to useful knowledge for an adversary if someone is willing to spend the time. But a lot of life is about tradeoffs. For me, I was able to get good enough privacy and significantly improved quality of life and improved remote security of my underground bunker by creating a “Smart Home.” Your mileage will vary.

* Check out Home Assistant if you are interested in going down this path.

** GE appliances require you to connect them to the Internet and use their app to utilize the “smart features”, other appliances may vary.

Barb and I visited Japan earlier this month. We were impressed with their attention to detail in what seemed to be everything. Everything was very clean. The public transportation ran on time. But we have seen that sort of thing in other places. I particularly noticed it in Germany. In Japan it seemed to dominate their entire culture.

On a larger scale there was this pond at Nijō Castle, just east of Ninomaru Palace in Kyoto. Just the maintenance of the pond must require the employment of many full-time people:

The guide told us of the buildings on different sides of the lake. Depending on the impression Tokugawa Iemitsu — 3rd Shōgun of the Tokugawa Shogunate (Title: Seii Taishōgun (征夷大将軍) — “Great General Who Subdues the Barbarians”) wished to make to visitors they would view it from one of four directions (via Copilot):

🏯 1. The Shōgun’s View — Absolute Central Authority

From the shōgun’s formal audience room, the pond presents:

• A dominant central stone grouping
• Subordinate stones arranged in stable, supportive positions
• A broad, calm expanse of water

This composition symbolized:

• The shōgun as the immovable center of the political universe
• Daimyō (feudal lords) arranged in proper hierarchy
• A peaceful realm created by Tokugawa rule

This was the view shown to high‑ranking daimyō — a visual reminder of their place.

👑 2. The Emperor’s View — Tokugawa Supremacy in Kyoto

When the Emperor or imperial envoys were received, they were seated in a different hall. From their angle, the pond emphasizes:

• The breadth of the water
• The scale of the garden
• The controlled, disciplined arrangement of nature

This communicated:

• The shōgun’s wealth and power surpassing even the imperial court
• A world ordered by Tokugawa authority
• A subtle assertion that the shōgun, not the Emperor, maintained national stability

It was a polite but pointed political message.

🛡️ 3. The Daimyō’s View — Harmony Through Obedience

Lower‑ranking lords were positioned so the pond’s islands and stones appear:

• Balanced
• Interdependent
• Harmonious

This was intentional symbolism:

• The realm is peaceful only when all lords support the shōgun
• Each domain has its place, and disorder is not tolerated

It reinforced the Tokugawa vision of a tightly controlled feudal hierarchy.

🌄 4. The “Public” View — Nature Tamed by Authority

For less formal visitors, the garden presents:

• Carefully pruned pines
• Asymmetry that still feels controlled
• Water that appears natural but is engineered

This view conveyed:

• The Tokugawa ability to discipline nature itself
• A society where beauty comes from order
• A world that looks effortless because power is absolute

Even the casual visitor was meant to feel the shōgun’s presence.

🎯 In short:

The pond was a political instrument. Each viewpoint delivered a different message, tailored to the status of the person looking at it:

Viewer	Intended Message
Shōgun	“You are the center of the realm.”
Emperor / Court Nobles	“Tokugawa power dominates Kyoto.”
Daimyō	“Harmony comes from obedience to the shōgun.”
General Visitors	“Order and beauty flow from Tokugawa authority.”

In between the large and the small was the Air BnB in Kyoto we stayed at. There was not a shower as we know it. There was a room with a bathtub and shower. The entire room was the shower with a drain in the floor. The toilet was in a different room and had a heated seat (with its own fan to dry your bottom after washing it). When you flushed the toilet the water to fill the tank came from what look like a faucet and dropped through a hole in the top of the tank. You could rinse your hands in the water to be used for the next flush. There was a separate washroom across the hall next to the shower room.

I bought some grapes. Instead of on the stem as you would buy grapes in the U.S., they were individual grapes. Each grape had about 0.1″ of stem still attached. I hypothesized it was to preserve freshness. Here is what Copilot reports:

🍇 Why Japanese grapes keep a short stem attached

🌱 1. It prevents juice loss and slows decay

When a grape is plucked cleanly off the cluster, the point where it detached becomes an open wound. That exposed tissue:

• loses moisture faster
• oxidizes
• becomes an entry point for microbes

Leaving a short stem stub seals that wound. The grape stays firmer, juicier, and lasts longer. This is the same reason Japanese guides recommend cutting grapes from the bunch with scissors rather than pulling them off.

🎎 2. It preserves the “perfect” appearance

Japan’s premium fruit culture prizes flawless skin and shape. Pulling grapes off by hand can tear the skin or leave ragged scars. Cutting them with a bit of stem avoids:

• torn skin
• bruising
• juice weeping
• cosmetic blemishes

For high‑end varieties like Shine Muscat or Kyoho, appearance is part of the value proposition.

🧊 3. It helps maintain freshness during storage

The bloom (the white powdery coating) and the intact stem both reduce evaporation. Japanese storage instructions explicitly say to cut grapes at the stem and avoid washing off the bloom to keep them fresh longer.

🎁 4. It aligns with Japan’s “luxury fruit” handling standards

Japanese fruit is often treated more like confectionery than produce. Individual grapes—especially large, premium ones—are sometimes sold separately, each handled gently and inspected. The short stem is part of that careful, almost artisanal process.

Copilot finished up with this:

Since you clearly appreciate the little cultural engineering quirks Japan sneaks into everyday life, the grape stems are just the tip of the iceberg. The whole Japanese produce ecosystem is full of these micro‑optimizations that seem fussy until you realize they’re actually elegant solutions to real problems.

If you’re curious, I can walk you through other examples — like why peaches are wrapped in foam nets, why melons are sold with the stem trimmed into a perfect “T,” or why apples are sometimes individually bagged on the tree to control sunlight exposure.

The smallest scale we noticed this attention to detail were with the toothpicks. We saw our first in a small (perhaps 6 tables) restaurant in Nagasaki, then again in an even smaller (a bar that seated about a dozen people), but much fancier restaurant in Tokyo. The toothpicks were identical and looked like this:

Individually wrapped, the surfaces were so smooth, the point straight to a square end, and with the precise grooves on the other end. I immediate thought these toothpicks must have been made on a lathe. And how different they are from the flat toothpicks in this country that you buy 750 of them in a box:

I asked Grok, “This is a toothpick I obtained in Japan. How was it made with such precision and the grooves at the one end?” I was correct about the use of a lathe:

This is a classic modern Japanese toothpick (called tsumayoji or sometimes “kokeshi toothpick” after the traditional wooden dolls whose shape the grooved end resembles). The grooves aren’t decorative—they’re a clever hygiene feature invented in Japan around the 1950s.

Purpose of the Grooves

The blunt, grooved end is designed to be snapped off at one of the notches after (or before) use. The broken-off piece then becomes a tiny stand you can rest the sharp end on, so the used point never touches the table. It also signals that the toothpick has already been used. This is why you’ll often see them in Japanese restaurants, hotels, and convenience stores.

How It’s Made with Such Precision

Modern Japanese toothpicks like yours are mass-produced on highly automated woodworking lines (mostly in Japan, though some are now made elsewhere using the same methods). Here’s the step-by-step process:

1. Raw material — They start with white birch logs (very straight-grained and smooth). The logs are softened, then peeled into thin veneer sheets on a giant rotary lathe (similar to how plywood is made).
2. Forming long rods — The veneers are sliced into uniform 30 cm (about 12 in) rods and dried. These rods are perfectly round and consistent in diameter.
3. Cutting to size — The long rods are chopped into individual toothpick lengths (usually ~6 cm / 2.5 in).
4. Shaping the point — Automated machines sharpen one end to a precise point using blades and sanding.
5. Creating the grooves (the “kokeshi” end) — This is the key to the precision you noticed.
   • Originally, manufacturers tried to smooth the blunt end with a high-speed rotary grinder because the cut surface was rough.
   • Someone had the idea of using a grinder wheel with an uneven notched surface instead. It cuts clean, uniform grooves in one quick pass while the toothpick spins.
   • The grooves also act as a deliberate weak point for easy snapping. This notched-grinder technique has been the standard since the 1950s and is what gives the end its perfectly even, professional look.

The entire process (except the highest-end artisanal versions made from kuromoji wood) is done by specialized machines that can churn out thousands of toothpicks per minute. That’s why the grooves are so consistent and the wood looks polished and smooth—no hand-carving is involved in the packaged ones you bought in Japan.

Some premium makers (like Kikusui Sangyo) still offer versions without the grooves to reduce waste, but the grooved style remains the most popular because of the built-in stand feature.

So the “magic” is a combination of clever Japanese industrial design from the 1950s plus high-precision automated woodworking—exactly the kind of elegant engineering Japan is famous for!

With just a little bit of effort we could see the design and attention to detail everywhere we looked.