I met a friend for coffee in an expat area of Beijing. Rode my bicycle, locked her up in one of those curly bike stands that permeate the sidewalks of Beijing, using my imported $100 U-lock. Naturally, I ran the lock through the frame & the curly bike rack.

Came out 90 minutes later, and the bike was gone, along with my lock.

My friend (a Beijing resident) bent over, and gave a push on the part of the curly bike rack that my bike was attached to, and the metal moved aside enough to create an opening that the thief would have used to slip the lock through. Releasing it, the metal sprung back to its original position so you couldn't tell. He told me this is an old trick - the thieves "modify" the bike racks and then wait for the opportunity - and an expat area is a prime location because many foreigners ride expensive bikes (although mine was a cheapish Giant hybrid - maybe worth $150). He said this rack has probably been a fruitful trap for months. No doubt.

Lesson learned. Shared FYI.