Seems like a bit of a consensus on calling out cyclists-gone-bad.
What about if you see a cyclist at night with no lights? Worth shouting something, if seems safe to do so?
One evening I was racing against sundown to get home from work and didn't have any lights. A white van pulls up beside me as we're moving down a mostly empty road, winds down window, and bald-headed passenger leans out to say "where are your lights, you c*nt"
Wanted to slash his tires but he did have a point...he's stayed with me that man all these years, and I remember him whenever I'm setting out without lights and it might get dark (and usually take some with me).
Justification for such shock therapy?