While everyone starts with the what-a-lovely-uniform-you-have-officer, we find that cheerful nodding gets harder to stomach once you've been fined once too often for miscellaneous visa paperwork, or after friends or family have been dragged to local precincts to answer for their non-existing connections with international Zionist conspiracies that may or may not threaten the Chinese salt supply. Which is not to say that we're bitter. But there's a point where the entire security theater starts feeling old.
So while we can't honestly recommend this way of dealing with the cops, if they happen to drop by on an early Saturday morning when you're still in bed nursing a hangover, there's absolutely nothing wrong with putting that pillow over your head and going back to sleep. If they think it's important they'll come back, and probably in about 24 hours with someone louder.