It's important to remember that the US concept of "free speech" as an absolute right is very untypical, and that it also has limits due to being narrow in its scope.
Of course, banning a social network due to arbitrary or without reasons would be against democratic principles. But following democratic and legal principles to openly apply laws and procedures designed to safeguard the state - that's not undermining at all, to the contrary!
[1] https://en.wikipedia.org/wiki/The_Constitution_is_not_a_suic...
The spying seems secondary to the influence they can wield by pushing certain stories while burying others.
For all democracy's failings, for the mess the US is in, and rise of populist parties in Europe, it is still freedom.
Citation needed. Last I heard it was mostly attributable to migration over the last couple decades.
[1] https://crookedtimber.org/2012/05/23/cognitive-democracy/