[Mediterraneo10]

What do you expect a librarian – who is, after all, not a trained security guard – to do besides simply call the police? And in so many of the examples that I see people complain about, it would seem that the disruption by homeless people or drug users is only noticed after it has taken place (e.g. they trash the toilets or leave needles or paraphenalia behind).

[kasey_junk]

Libraries can hire security (and most around me have).

It’s a sad outcome in it means less funds for library services but it’s better than libraries not being used because people feel unsafe.

[mynameishere]

What an odd "problem". I would expect the librarian to call the police. And if there was a "trained security guard" on the premises I would expect him to also call the police.

(That's why we have police.)

[dazc]

Clearly you haven't encountered the Police in the UK. Unless it's a life or death emergency situation the default response is often one of disinterest.

[the-red-herring]

Well, you can't rely on police for everything. I mean, they aren't your personal dobermen.