+1

Happens around here occasionally, on the road and on the MUP. In my experience, the individuals are usually pretty clearly pathletes or Cat 6 "racers" -- in other words, idiots.

I don't like being shadowed this way; I ride alone, by preference. My usual pace is certainly not fast, but neither am I particularly slow, so I do get the occasional leech latching onto my wheel. My response is typically to start slowing down -- and down -- until he/she finally gets the idea and goes past. The entertainment bonus is that my slowing down often initiates an amusing "sprint" pass from the drafter accompanied by 'the Look of Triumph' as he/she goes by. Turns an otherwise irritating situation into a comedy sketch.