According to Zuckerberg, the FBI was pressuring them constantly to censor in 2020-2021. They couldn't speak up about it for a host of reasons, mostly around the fact that they are a centralized entity that has to do what the governing authorities tell them.

Extrapolating out, we can assume that such shenanigans have been and continue to be at play for every centralized company to keep the regime's narrative going. This is why Nostr is so important.