I'm torn. Freedom of speech and freedom of expression mean that the government can't put you in prison or punish you for saying or believing what you do. Facebook aren't the government, they're a private entity and don't have to host anything they don't like- including hosting photos that they don't like. It's a walled garden, and it's their walled garden, and if you don't like it you're welcome to leave. And on the…
So just playing the "but it's their walled garden" card does not cut it for me.
For me the question is whether facebook has a significant influence on the population or not. I think they already do when it comes to News, more so than traditional news organizations even. On top of that, they claim to provide an open space for exchange and even discussion.
Personally, I'd therefore like to see facebook being regulated to the point where they cannot simply refuse "service" to people of certain completely legal opinions discussing legal topics, same as they and other businesses should not be allowed to refuse service for certain classes of people.