I used to work in the 5th busiest library in Illinois five years ago (Cook Memorial Public), and the rate at which the condition of that library deteriorated was astounding. I had gone to that library from 2nd grade until I graduated high school (and quit my job, I was a high school page at the circulation counter), and my mother had worked there from the time we moved to the town until we moved out.
That library was a haven for my friends and me growing up. We'd go almost everyday just to escape the heat or brutal cold and we'd grab a bunch of books and magazines and hang out, and whatever we didn't finish we took home. Once I got into high school, I would go there every day to check the CD racks and the video racks to see what new and awesome random thing I could find. Once I got a job there, though, in '03, things went downhill, fast. DVDs were steadily becoming more commonplace, and the library had a pathetic DVD section, so, naturally, everyone began to demand the library update it's video section with DVDs instead of VHS. Contrary to popular belief, when you request something at a library, they can't just turn to someone and say, "I need this," and then give it to you. It costs money, and libraries have very tight budgets. What's unbeknownst to most people is that, while you do pay taxes which go towards paying for public services such libraries, very little of those tax dollars actually make it TO the library. The library's budget is entirely dictated by the town government, and anything the library wants has to be passed through by not JUST the tax paying voters, but also the town board. This leads to very angry patrons, because they can't have what they want and so they pressure the library until they get what they want. This leads to job and service cuts just so Soccer Mom can have Dora the Explorer DVD for her little girl.
Then the internet got huge. As if getting every new CD and DVD wasn't enough of a problem, now we HAD to get free, unlimited wi-fi, and we HAD to get brand new computers so everyone could go on MySpace. What ended up happening is just like in the OP: we gave the masses computers, and they trashed the fucking place. Everyone treated it like a rec room and would leave trash all over the place and would bring in drinks and food and leave them behind. People would get their books, along with their coffees, go sit at a computer and place the coffee on the stack of books and then, OOPS, down goes the coffee ruining a stack of books and a brand new computer that the library can't replace. But, oh no, people began to complain that one of the computers was down and couldn't be used. Threats were made, and the library got a new computer.
Dozens of people were laid off just because the library had no option but to update to the hot-new-thing everyone wanted. The library is a free-public service, but it still costs money. It's a business of it's own, and a lot of people fail to realize this. TL;DR, whatevs, I wanted to get that off my chest, because libraries and librarians get a lot of shit for no reason.
edit: the Children's department is a whole 'nother issue.