The recent killing of a bike messenger by a car in Toronto has spurred a great deal of debate about cyclists, cars, and their behaviour on city streets on most popular media here in Canada. It has become quite apparent that some people really don't approve of bike messengers or cyclists in general, and messengers and many other cyclists are quite prepared to hate them right back.
I've got just a couple of things to say here.
Bike messengers are not representative of most cyclists. To put messengers and cyclists into one bucket is like saying that all motorists are just like long haul truckers. The differences between what urban core messengers do and what most commuter cyclists do are huge. Many bike messengers also live in a subculture that is not particularly mainstream, and I think many who bash them are as much annoyed by their failure to meet certain social norms as by how they ride. All that aside, there is something else important to say.
Bike messengers are specialists who are PAID by people working in urban centres to RIDE LIKE THEY DO. People pay them precisely because they can move aggressively through dense downtown traffic. If you've got a beef with the way bike messengers behave, go tear a strip off the nearest downtown office manager, or lobby local politicians to ban the business. Give these people doing something terribly risky in order to make a living a break. As specialized and seemingly reviled as they are, it is no wonder a subculture has grown up around them. They need it as insulation from all us hypocrites.