we have been asked to do this before and always said no. Firstly, we have no way to do it except by physically calling up each and every post you've made and deleting it - an extremely time consuming business to ask volunteers to take on. The other problem is that removing posts disrupts the archive - we can't pull all the responses to you, so we have threads that make no sense anymore.
You are, of course, always free to edit your own posts - just click on the pencil icon at the top of your post and you can get back in and remove anything you no longer feel comfortable with.
Please do drop me an email if you want to discuss this further.