I used to be a lot less calm about idiot cagers... and I have probably put myself in more danger than necessary.

Example:
I was riding a deserted 4 lane divided road... not another soul on the road. My mirror showed me a Corvette roaring up behind me, and the guy buzzed me within a couple of feet of my elbow despite having two empty lanes to give me some room.

I caught the guy at the next light, and while he smirked at me from behind the wheel... I calmly spit in the palm of my glove and carefully placed that hand on his hood to balance myself.

It didn't take me long to realize that I was pissing on a guy who had already proved that he didn't mind using his four-wheeled missile to intimidate. He may just use it to hurt me if he got the chance...

Nowadays I just smile and wave at the jerks even though I'm roiling inside. They're not worth it.