Well, they're not locking their bikes to bikes, but locking posts in the shape of a bicycle. This may exist elsewhere, but I've only ever seen it in Germany.
In Denmark, people are so trustworthy, bikes are often only locked to themselves, if they're locked at all. I walked past many a fine bicycle that was only locked to itself so you couldn't ride it, but could easily be picked up and carried.
On the streets of Toronto, those bikes wouldn't last five minutes.