"Censorship is suppression of speech or other communication which may be considered objectionable, harmful, sensitive, or inconvenient to the general body of people as determined by a government, media outlet, or other controlling body."
http://en.wikipedia.org/wiki/Censorship
Speech or other communication which may be considered objectionalbe, harmful, sensitive, or inconvenient to the general body of people as determined by a controlling entity is relative to the one that makes that judgment call.
Banning an individual from a forum, or a threat to ban someone from expressing themselves in a forum, is censorship.
In other words, a moderator can be influenced by someone that has a habit of hitting an 'alert' button for every little thing that they feel scratches their skin (or rather, the skin of their ego). Instead of examining, and/or re-examining, what lay behind their own feeling that their skin has actually been scratched (or not) when they read a few words strung together across a white background. Especially, when one chooses to enter a debate forum out of their own volition.
In this context, the prescence of a moderator can prevent a habitual 'alert' button pusher from looking introspectively at themselves as to why they feel they are a victim. This may actually prevent such a person from rising to a level of maturity whereby they don't need a nanny to take care of them.
(To the mod: I hope you don't take 'nanny' as being a dig on you. Its just my way of expressing what I see as the role of a moderator.)
Certainly no one should censor information because of their private agenda or because they disagree with something. However, there are times when editing is appropriate. For commercial links in otherwise good posts. Or, derogatory comments directed at another member in a post that otherwise has valid information. One of the best moderators in all of CZ in my opinion, does both of those things consistently and silently behind the scenes. It does take a bit more effort, but I think it is better in some instances than limiting the choices to either removing the entire message or else letting the part which offends or violates TOS stand.