Trust me, you can be anti-meek and still get hit or almost hit. I'm very anti-meek, taking the lane where it makes sense and riding right in the middle of it, and I still get asshats who don't see me (despite helmet light running during the day), misjudge speed, or generally are clueless. I have people who blast past as I'm trying to cross, people who lay on the horn as they speed up, and people who slow down, act like they're going to stop, and creep by.

If I got any more aggressive, I'd be playing chicken, and I don't particularly want to die. This is something the VC evangelists don't get - there are many places where you can be as VC as you want, and cars will still do dumb stuff. VC has its uses, but it's not an antidote to vehicular stupidity.

The best weapon I have now is startling them, as you mention. I yell 'STOP!' very loud. That's the great thing about being in shape - it gives you a helluva lung capacity, and I use it. The other thing that I use is my helmet light - if I'm afraid someone doesn't see me as I approach from the side, I shine it in their direction briefly, enough to get their attention without blinding them.