Hey, i am not a big fan of facebook or twitter either, if you aren’t paying for a product, you are the product, and all that.
Still doesn’t make it socialist. Definitions matter.
Because socialism is "communal ownership of communal labor." Facebook is a private corporation. Even on the micro, user scale, it models private property. Tribal behavior =/= socialist
Corporations are legal entities of government. It models private property within a mixed market, making it socialist: your data and posts are owned by fb.