Ok Youtube for example has had a longstanding policy of removing videos using music clips without the rights (I assume proactively, not just in response to DMA notices). This is essentially an automatic mechanism, possibly overly aggressive, to stay within the law- find unlicensed music and silence the video. But like stopping me from infringing on a Metallica song is clearly categorically different from actually censoring a video about Coronavirus that doesn’t comform to some standard or is accused of spreading misinformation.
I brought up copyright as just one example, these platforms have many reasons (not always given) for deleting stuff, ranging from political content or activism to copyright. Most ToS's are quite arbitrary. People have been talking about this for a long time as well -- "Chilling Effects" turns 20 this year! At the risk of being a bit unkind it seems like it's mostly just conservatives who were "living under a rock" until now, and now suddenly have loads of opinions on it.
