It's okay :P
For whatever it's worth, LOTS of upgrades/mods done to bikes are technically illegal. Fender Eliminators, Aftermarket Exhausts, etc.
Also, not trying to be a jerk but the original line used was "very little gain" not "of questionable legality" -- I think you're just searching for a justification Joshorilla.
Anyway, I'll keep up with the research and see what I can find. If I do it I'm going to do it right and thus won't be blinding anyone. I'll also check and find out which states use DOT headlight rules and which don't (interesting fact for those overseas: in the US road laws are set by the individual state, not the federal govt).