#bins

Genuine question (idk if other countries outside of Ireland have this but), why is there signs on bins, usually in cities, not allowing people to take things out of the bins? And I'm talking in relation to homelessness. firstly, we have the return bottle scheme in Ireland (for those who don't know, is where plastic/cans can get returned to be recycled for around 15 cent), and I see a lot of people, in urban and rural areas, collecting bottles off the streets to get money from the return scheme (both homeless and not homeless do this). But a lot of people take bottles from the bins and return them from money, and I am nearly positive that if the bottles were not taken from the bins by someone, they would get put into a landfill. And I understand it's not hygienic to be taking things out of a public bin, but sometimes it's the only way people can get money, apart from begging on the street. And I think people with common sense understand that. So why are there signs prohibiting taking things out of the bin?