Actually, what bothers me more is when someone doesn't pass you but rather latches on my wheel without me knowing it. I suppose it is gratifying that somebody is willing to draft of a middleaged guy in shorts on a befendered bike, but pretty dangerous. I almost got hit from the rear 5-6 years ago when the cyclist maybe about 50 yards in front of me abruptly went down on a steep downhill. I started braking sharply and immediately hear this, "whoa, whoa, whoa" from behind me. I let off the brakes instantly and then slowed gently, there was this totally shaken guy who had been tailing me w/out me knowing it.

This happens fairly often to me around DC to the extent that I now glance back pretty regularly if I am clipping along. If I do find an unwanted stealth drafter, I address the situation in no uncertain terms, pointing out that they should be ashamed of drafting off old/slow guy like me, maybe a bit of safety lecture & slow down & make them pass.

Fortunately, although I'm uncertain of how fenders would complicate this situation and I really don't want to find out, they are likely the first ones going down in a wheel slap which proves that there is some justice in the universe.

It always is news to these guys that it is a bad idea to sneak up on someone and ride a few inches off their wheel w/out the other guy knowing. Really, genuine, honest astonishment usually. When I'm regularly riding in season here, seems like this happens at least once or twice a month.