The number of urls is not relevant. If you edit a post, shouldn't you indicate that? If you change someone's language in a post, it seems it would behoove you to "bring attention" to it. It would piss me off if something I posted was altered without indication. If you don't like **** then put the word [EDITED] or [CENSORED] in place of the offending language. IMO language at the bottom indicating that the post was "Edited by Druff" doesn't go far enough, but it sure as hell beats nothing!
It's not good to alienate your posters.