That would depend on why you wanted to break the links.
If it was a "work in progress" that you wanted help with, you're allowed to use a link shortener in that instance (although not one that uses affiliate links or anything like that – just stick to the main ones like bit.ly and so on) – we understand that developers don't want a Sitepoint Forums discussion outranking the live site being discussed!
If it's something that you posted in a fit of youthful exuberance, and come to regret with the wisdom of maturity, then I'm afraid that's hard luck. Without wanting to sound harsh, we've got better things to do than run around clearing up after you because you opened your mouth without thinking. A good rule of thumb, for anything you post online, is to ask "would I be happy for a future employer to read this?", and if the answer's "no" then it isn't a good idea to post it!