The government saying that you can not publish something is censorship.
You must be working from a different dictionary than me. Censorship is when something is deleted or hidden from view. There is no requirement on who is the one doing it.
If I decide not to say "fuck" in this post and replace it with "fudge", that's self censoring.
If a newspaper removes the word "fuck" from a letter to the editor, the newspaper is censoring.
If Google hides all adult content from view, Google is censoring.
If the Government tells a newspaper they can't run an article critical of it, the Government is censoring.
Only one of these things is illegal.
Just because Google is censoring adult themed websites doesn't make it wrong or illegal. You can't decide that a word means less than it does just because you don't like the connotations.