This seems like a fairly antiquated view that does not map well to the current era or actual definition of censorship (A cursory internet search will help to better inform you as to what censorship entails and what actions may reside within the purview of censorship).

One does not have to prosecuted by the government in order to have their speech censored, access to a public forum revoked, or have their livelihood and career threatened.

There are things you simply cannot say within our society due the fact that they are deemed subversive or improper. This arbitrary ability to ascribe these labels to speech and thereby limit its reach and punish those who speak it is the very abuse of power that is characterized as "censorship".

A government is one institution that concentrates power that can be a censor, but in modern times there are alternative organizational structures that are both powerful and global that can perform the act of "censorship".