- location based chats, you see people around and can start a local group. So you can easily get in contact with other protestors around you.
- Broadcasting channels
- Not by default, but you can creat encrypted chats, with auto destruction
- Since a few days, encrypted video calls
- Not owned by Facebook
"nine out of ten Egyptians and Tunisians responded to a poll that they used Facebook to organise protests and spread awareness" [1]
"During the Arab Spring the number of users of social networks, especially Facebook, rose dramatically in most Arab countries, particularly in those where political uprising took place, with the exception of Libya, which at the time had low Internet access preventing people from doing so" [1]
As far as I'm aware Facebook is actually owned by Facebook.
[1] https://en.wikipedia.org/wiki/Social_media_and_the_Arab_Spri...
Keyword "public". It is the same useful for protests as it was then.
And you have a huge difference between Facebook 2010 and 2020.
Careful though, since video calls are currently in alpha.