Thankfully, I've not heard of that around here. The public library I worked at was chill about everyone visiting, including several people I'd consider "problems": dude that always sat next to the teen section and complained the teens were loud while being louder than any teen, and other dude that would sit in the middle of a row of public computers and turn off the ones on either side because she didn't want to sit next to anyone else.

The only time we kicked anyone out was when someone was vaping. The only time someone got banned was when they were racist in response to being told they couldn't vape in the library.

ETA: "around here" is suburban New England