I like to pedal silently up behind other riders, then stop pedaling and scare the crap out of them with the incredibly loud freehub on my Fulcrum wheels - BZZZZZZZZZZZZZZZZZZZZZZZZ!
Just kidding. He should have announced himself.
If somebody grabs your wheel that you don't want, just start riding erratically - wander all over the place, speed up, slow down,sit up and coast a bit, aim for a giant pothole and pass within an inch of it - they'll stop.
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"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles