Facebook has admitted in a defamation court case that the “fact-checks” used by the site to blacklist non-corporate media content are actually opinion-based labels, therefore they can’t be sued for their smear campaigns because they are not actually asserting facts.
Imagine calling something a fact, and when someone says “is that true though?” you say “hey it’s just my opinion, man”.. and then you smugly call yourself a fact checker.
An extract of their legal defence: