Earlier this evening, as I was sitting on my couch reading a book, my doorbell rang–frantically, as is often the case in China, where it seems the person ringing the doorbell thinks that the person answering the doorbell should be able to open the door within 1.5 seconds.
I opened the door thinking that it would be the water meter reader, so was quite surprised to see four rather large uniformed policeman standing there. They informed me that they wanted to see my passport and residence registration papers. I said "sure, I'll get them for you," and left them at the door chattering away about the foreigner who was talking to them in Chinese!
Fortunately, I knew right where the registration paper was. "Here you are," I said, "I do everything according to the law!" — at which they all howled and chattered on about the fact that I could speak Chinese.
They thanked me, handed back my passport and papers, and went on their way.
I'm not sure what that was all about. Maybe just a random check on foreigners' registration papers. Maybe something related to the 2010 census.
I am sure, though, that it was the first time in 25 years I've had police show up at my door wanting to see my papers.