Check out this gallery of prank signs from the London Underground. Many of them crack me up, none more so than this:

A) More people should put up signs like this on the New York subway. I demand entertainment.

B) My high-school friends and I did something similar in our school’s library. For whatever reason, the librarians had handwritten signs in various spots on the library outlining library rules. They were just black ink on printer paper held up with Scotch tape, so they were really easy to duplicate. Most of ours were so outlandish that the librarians would notice them and immediately pull them down. But at the end of every semester when they did their inventory and cleaned up, they’d always wheel out a rolling cart of books with a sign attached that said, “USED BOOKS! Take them if you want — they’re free!” At some point, one of my friends replaced the sign with a nearly identical one that said, “USED BOOKS! Take them if you want — they suck!” And it stayed there through graduation.

I’m sorry, librarians and former librarians of South Side High School. I was such a jackass.