Sure it can t be applied to all restaurants but cyclists can choose their place of choice based on how cycling friendly they are.
I also sticker bombed one of my bikes so that if someone were to steal it, it would be very easily identifiable.
Usually, they're just...gone.
The police around here do collect bikes that they find dumped in places where they don't belong -- in parks or when reported in random folks' yards or wherever. These get auctioned off if not claimed first.
But I did get my bikes back a few times.
Most memorably, I was doing some random technical work at the local PD and was heading out to have a smoke, and I saw a bike that looked just like mine just standing there on the back dock. Same purple Caloi aluminum frame, same additions (like the 90s-style Control Stix bar ends), same everything, except it had an inventory tag on it.
Which very seemed strange to me, since I knew very well that my bike was safe at home. Or did I know that? Maybe my bike wasn't safe at home. Or maybe someone else had the same mods on their own bike, which wasn't particularly unlikely since I bought all of it from a singular bike shop in town?
So I asked about it. And they're like "Well, if that's your bike, then maybe you can tell us something about it that is identifiable. Something unique that you couldn't see in the five minutes you've been standing there staring at it."
I couldn't think of anything. But that ultimately didn't matter -- they were fucking with me for the lulz.
"Maybe you don't remember doing this," they continued, "but it's got your name, address, and phone number engraved on the bottom of it."
Fuck! I did put that on there over a decade prior, and I completely forgot. That certainly was convenient for future-me.
Anyhow, it took a couple of days for them to finish their bureaucratic paperwork dance, and then I had my bike (that I didn't even know I was missing) back. Thanks, in large part, to having some identifying features.
Depends on where you live, of course.
Theft is a big issue during the transition phase when a city is becoming more and more cycling friendly and a lot of people are actually looking for a bike.