In Japan many people use flimsy locks on bikes. It is not to deter a determined thief, but to mitigate the possibility of an opportunistic "borrowing".
Just about all the bike locks I've seen here are flimsy, and most only used to lock the wheel to the frame so it can't be ridden away. Most bike thefts are from drunk salarymen "borrowing" a bike to ride home (riding while drunk is illegal BTW, just like driving drunk).
I've the same about the Netherlands. Everyone knows it's a country with huge bicycle ownership and use, then later people discover it also has huge bicycle theft. From talking to people that have lived there, anecdotally all the theft is drunk or mistaken "borrowing".
