I really can’t say I blame them. There are only three kinds of common bicyclists around here: kids and can collectors (who bike on the sidewalk) and spandex aero guys (who keep as far to the right as possible and never turn left). As a commuter who practices vehicular cycling, I’m both an oddity and a weird obstacle they aren’t used to dealing with.

So far, though, they’re only using their horns and I can pretend they are honking at me because they think my bike is so awesome.

I caught up to them at a light, I was on their left in the left turn lane. I looked at the driver and said, “Sorry, I didn’t quite catch that.”

“Nothing. We weren’t giving you a hard time. Nice bike.”

“Thanks,” I said. “Call your moms today. It’s Mothers Day.”

“Okay.”

Then a car went by and a woman (I’m pretty sure a passenger, not the driver) hollered truly threatening direvtives… and it was with precisely the psychology of the teenager on the bus that snowy January who was trying to get into an all-out brawl with the other lady on the bus, and one of them showed a knife and the other made a big obscene and hostile issue of that and police were brought in to the scene…
… I wasn’t on a bus, though. I’m thinking that there was probably something going on and she’d been the loser, and now she had to win… if the vehicle so much as slowed down, I’d simply have turned around — the cops were about 100 yards behind.
However, nobody takes hollering out the window at you as a serious threat… even if you’re femail, and it wasn’t worth raising my blood pressure over (and it didn’t – it was so out of context I sort of observed it like a TV show). I don’t think she was a career VT, though she could have been at that point…

If someone were to behave in a truly aggressive fashion, though, I’d try to get the plate number, or at least a vehicle description, and report it. The Northampton (Mass.) Cycling Club had a thread on its discussion board a couple years ago about an aggressive pickup driver who had made threats against several cyclists and had threatening anti-cyclist messages in her truck windows. The police tracked her down and had a discussion; apparently that took care of the problem, at least in the short term.