It’s meaning in abstract is simple, but it’s actual manifestations are usually quite complex. Self-censorship for example: If you self-censor out of fear of a negative social reaction, to what degree is that actually someone else stopping you from talking? Everyone else, or the idea of everyone else? I would say that any view that’s held by a group of people that’s pervasive enough to cause others to calibrate their words towards them, any cultural context strong enough that visitors feel a need to adjust for it, automatically and unconsciously practices censorship.
“Don’t call my home phone, I’ll be out seeing the new Matrix so you can just page me instead.”