It's interesting to note that the man apparently did nothing criminal. This is a civil matter between him and the library, as though the library were a car mechanic or a dentist that he reneged on an agreement with.

I feel like someplace else might have recognized what I think can fairly be called hate speech, destruction of the commons, and terroristic intent (on a very small scale -- destruction of the commons specifically for political effect). Certainly he's not morally superior to someone who throws soup on a painting or glues themselves to the road for climate activism. I think such activists frequently catch pretty grand charges.