i don’t see the problem with this tweet (assuming that it’s true, which feel free to correct me if it’s not)
a very cursory search shows Rage Against the War Machine is a Libertarian Party event, which means at best right-wing libertarians and more likely outright fascists who are cynically using calls for liberty to immiserate and oppress minorities. good on the PSL for attacking them.
This is pretty common among conservative books (and other media more generally). It’s produced to give people who already agree with it confirmation that they are right (“It’s in this very authoritative book!”), not to convince anyone or convey new or interesting information.