They are effectively unregulated. Most drivers have no clue how to adjust them, and the "modders" replace them randomly with whatever they find is the brightest/coolest. Yeah, you _could_ fine them and claim that the cars are unroadworthy until fixed, but if a rule is not enforced, is it a rule? So, yeah, effectively unregulated, too.

I bicycle a lot and I tell other cyclist that they need to adjust their lights all the time. At least they seem to take feedback. Somehow, drivers think that they, in their multi-ton metal boxes are a band apart, and tend to take zero criticism from anyone outside of their metal boxes.