Hmm, it is a good question!
Try to post to the Feedback Forum... or try to Report post in the thread you want to remove.
Note that in any case you will have to argument the reasons why you'd like to remove the whole thread!
Alternatively, at the bottom of the forum section page (the one that lists the threads), you find a list of moderators of that specific section. The moderator names are clickable links, taking you to each moderator's individual profile page where you can write a private message to the moderator (unless that moderator has disabled PM, but I don't think mods do that).
I was thrown out of college for cheating on the metaphysics exam; I looked into the soul of the boy sitting next to me.
This is a snakeskin jacket! And for me it's a symbol of my individuality, and my belief... in personal freedom.
Thread must not be empty! Otherwise it would confused all the people accessing it.
Well, you can edit your post, but please, don't leave the post empty! Instead, describe the reason you had to edit it.