The FBI did
this to a child porn perv who posted the pic (on the left). Only reason they were able to reverse it was because all the information was there, just swirled. If you pixelate it, then it's harder to do because not all the info is there.
Read
this
If you don't want your face online, the best way to do it is not get it in the photograph at all.
You can ask the mods to remove the pictures, but why? If you have a showcase, most of the time that's the picture used. He cannot post a picture that you don't let him take.