Every place in the world does probably. But how would you prove an unmarked, cheap bike was stolen?

You wouldn't but nowadays no bike is unmarked, even the cheap ones.

Can’t you trivially deface an identifier?

In Belgium, it's a hard to remove sticker on a consistent place with a qr code.

It would take work to remove it cleanly and/or cost money/time to paint over it.

So it's less attractive.

Ps. You'll still need to take care of your 10 k. Bike ofc.

Ps. 2 : engraving isn't done anymore since bike frames got smaller.

How would you know a marked bike was stolen? Does the police offer a public listing of all the stolen bikes?

(I do not think so, but this probably would make sense)

If you can't and the owner can and if you are caught then you are liable.

If the seller threatens to "steal it again".

The Netherlands famously has more bicycle thefts per year than citizens. At this point you could almost think of cheap commuter bikes as public property.

People in countries where bicycling is not seen as a personality statement generally ride very cheap city bikes around town. Last time I bought one of those in college it cost about 30eur. Is not like in SF where people ride 3000 dollar bikes to work because omg you’re a cyclist now and this is your whole identity.

Here in the part of Canada I live in, you see some of the $3000 bike identity stuff, but most people ride something in the $500–$750 range. Something practical, comfortable, reliable, etc.

There is also a growing segment of people who use $5,000–$15,000 cargo/kid carrier bikes as replacements for their cars, which is cool. But I do worry about theft of those increasing. Right now I rarely hear of it, but it seems likely to increase. Even the motors and batteries in them cost thousands alone.

> think of cheap commuter bikes as public property.

Didn't Amsterdam try that with 'white bikes' in the 1970s?

> The Netherlands famously has more bicycle thefts per year than citizens.

No, it definitely does not!

750k bike thefts for 17.7m people. So roughly one per 25 people...

It famously has more bicycles than people!

Of course they have more bicycles than people, the bikes keep getting stolen!