I've been to some libraries where it's for whatever reason full of people either drunk or high causing a ruckus. Then they sometimes fight, leave needles and stuff behind and yell at random people. The library has hired/asked the mall to get more security, but the library has already got a reputation and people have started avoiding it. It sucks, there's very few nice, calm and quiet community places around.
The situation improved this summer since the drunk or high people spend more time outside but now the close by park has been dug up, so they're back to the library.
It's not really homeless people that do that here, it's more just generally addicts. Still sad and a poor situation for everyone.
Most libraries aren't like that though, this particular library just has it bad. I'm not exactly sure why