Cyclists like those you describe irritate me too. Last year DH and I were out riding, and had a couple of cyclists blow through a 4 way stop about 1/2 mile ahead of us cutting off a car that was turning. They then proceeded to ride down the center of the road (2 lane).

I was so pissed, I took off after the cyclists. I planned to tell them how bad their behavior makes it on the rest of us. When I finally caught them at a light I was so winded I couldn't say anything!

DH and I still laugh about that.

They took off and that was that. I try to do what Knotted Yet does, be a goodwill ambassador on a bike. A couple of years ago I read an article in Bicycling by Bill Strickland that convinced me that's the best way to ride. Not always easy but smart.