This seems like a good week to post this:
That's the classic Buster Keaton short Cops, in which our hero has a run-in with the LAPD—and I mean all of the LAPD. You should watch the whole thing, but the part with the police starts about 10 minutes in. Keaton fans will note that the crowds of cops here play roughly the same role that the crowds of cows do at the climax of Go West.
(For past editions of the Friday A/V Club, go here.)