I don't think they're state-owned, but they depend on community and county (and maybe state and Federal) sources for funding. Depending on the community politics, libraries could face funding cuts for running exit nodes.
If the library staff are at all bureaucrat-savvy, they can probably obfuscate the activity. I hope so. I think this is a very good idea.
I think he means state-owned in the sense that the IC can easily watch the traffic going to and leaving the exit node, and with many exit nodes leveraging this into a passive attack on the network.
If this is true, if ToR is to stick to a goal of establishing truly anonymous browsing, ToR needs to establish links through a diverse number of jurisdictions.
If the library staff are at all bureaucrat-savvy, they can probably obfuscate the activity. I hope so. I think this is a very good idea.