I think this is a non story. "Opinion" has a legal meaning. What Facebook is saying with the badge is "we think this post contains false information based on th

I think this is a non story. "Opinion" has a legal meaning. What Facebook is saying with the badge is "we think this post contains false information based on this other fact checking article", and from there they have to argue whether the opinion is protected or not protected, since prefacing "IMO..." does not actually protect you from libel laws. You'll see in the filing the lawyers also argue the actual fact-checking article is "neither false nor defamatory". The second part is important because if you base an opinion on false facts, then it's not protected speech. IANAL