Why should you have this concern in mind, have you experience any discomfort with that, though i don't think there's a function to do that but you can always Logout your account and delete the browser used as well and clear the cookies and caches, this is the best and easy way to stay off the forum incase you choose to, but on a rare condition I've come across this kind of experience whereby people want this same request you required, but it's something you can always do, you have the right to choose the site and things you do whenever you're connected to the internet, deleting account by self may not be possible but you can remain inactive and the account remains like that which took nothing away from you either.