On top of that, the image reminds me of some memes I saw more often a few years ago, of church marquees with snarky or funny pronouncements on them, that turned out to have been made from image-editing software templates. This meme might have been made with just such a tool. The word LIBRARY in this one is a giveaway: wouldn't a real library include its name on a sign like this?
But of course, not everything in a library is true either, even if you leave the Internet out of it. Numerous commenters pointed to fiction, and others argued that fiction is labeled as such. Usually, yes. But in the non-fiction section you'll find various religious scriptures and commentaries thereon, books on the paranormal (UFOs, telepathy, the occult, etc.), political polemics (my local library has plenty of Trumpian and other right-wing propaganda, which greatly outnumbers its left-wing counterparts), dubious popular science, and so on and on. That you find something in your public library's stacks is no guarantee that it's true. Despite some people's claims that librarians are gatekeepers, they don't and can't vet everything they acquire for truth or accuracy.
And as I keep insisting, the Internet makes it easier than it ever has been before for users to check facts. Most people don't, but the Internet didn't create the problem.
