I have read some wonderfully articulate replies in this thread. I don't think the reply, 'What were you doing looking at this site?' is enough. It doesn't protect you from the unashamed snooper who knows you from telling all and sundry. It is the rumours that get magnified and twisted.
As for myself, I put a picture of my face on my profile but like so many people I am sensitive about my looks and wished I looked more attractive. Despite my reluctance I put my picture there out of honesty. I guess it puts a lot of people off though.