I agree with your argument and conclusions except that I think you're using a narrow definition of censorship. If we accept your definition, then it follows logically. But I don't think most people understand the "threat of violence" part of the definition that you use, and therefore by the more widely understood definition, they are using the word correctly.

Censorship is the suppression of free speech, public communication or other information which may be considered objectionable, harmful, sensitive, politically incorrect or inconvenient as determined by governments, media outlets, authorities or other groups or institutions.

Edit: When I wrote this, the argument at the end of his post wasn't added. I don't think the word used to mean what @dantheman believes it did. Many here view things in light of the use of or threat of violence, but the wider public and historic philosophical thought was not always so focused on this.