Moreover, depending on the contents of the list, this likely offers proof of what is generally suspected, that the no fly list is a form of discrimination and authoritarian overreach, targeting people that haven't been convicted of a crime but are "suspected" due to race, religion, etc. The whole thing is probably unconstitutional/illegal, but it's hard to prove that since it's been secret.
This seems like a clear case of hacktivism- trying to expose an unethical government program for what it is, so that it can be stopped.