I once almost had my cover blown but my quick thinking saved me.
Some one said to me “Hey you have to see this, some one is impersonating you. Check out this website called ‘The Yeshiva World’ and go to the ‘Coffee Room’. There’s a thread there called ‘The Riddle Thread…’ where someone goes by the name Dr. Pepper and asks the same kind of riddles that you would.”
I said “Oh, it’s probably a former student of mine. Can you do me a favor? Tell the guy to get a life. Thanks”
The person must have just been a lurker because they never posted it. That was the closest call I ever had.