Part of the problem is the increasing use of public libraries for after-school day care. Parents send their kids "to the library" -- hey, it even sounds like a good thing. Kids as young as 5 or 6, left unattended, or watched by their older siblings.
It's free, it's "educational", and it passes off the problems to the state. Librarians are loathe to take action, because "where else do the kids have to go"?
There are a LOT of kids growing up without parents. Well, they have parents, but they see very little of them. It's almost like "Lord of the Flies", but as a day-trip.
Where else do they have to go? I tell you what: lower the drinking age and let them go to bars. They couldn't behave any worse, and if they drink enough they will pass out, thus cutting down on the time they have to annoy the rest of us. Get this, Librarians: libraries are not holding tanks for miserable kids. If that is all they are being used for, then shut them down.