My philosophy: If you've missed hitting the person who has just cluelessly and in most cases, unintentionally has tried to "take you out of circulation", even by a inch, just shake your head from side to side in a paternal manner(you people remember when your Mom or Pop did that don't cha?! How did you feel?! You didn't "flip them off, did ya?) at the inattentive cager, and they usually get the message that they should "maybe" be juuuuust a little more observant out there.
I find this course of action a little more conducive to a "meeting of the minds".
I used to follow 'em and give 'em a piece of my mind(that's why there's sooooo much less of it nowdays...my mind, that is), but I've grown up a little since then.
BTW, if they hits cha? Sue the crap out o' 'em. That's what lawyers are for!
(I know, I know, this isn't the most "macho" course, but I've found it much more effective in the long run)