They are also breaking the law in Ontario, Canada (where this happened), where lights are required on bicycles at night, where the highway traffic act states:

Motor assisted bicycles, bicycles and tricycles, lights on, etc.

(17) When on a highway at any time from one-half hour before sunset to one-half hour after sunrise and at any other time when, due to insufficient light or unfavourable atmospheric conditions, persons and vehicles on the highway are not clearly discernible at a distance of 150 metres or less, every motor assisted bicycle, bicycle or tricycle shall carry on the front thereof a lighted lamp displaying a white or amber light and on the rear thereof a lighted lamp displaying a red light or a reflector approved by the Ministry, and in addition there shall be placed on the front forks thereof white reflective material, and on the rear thereof red reflective material covering a surface of not less than 250 millimetres in length and 25 millimetres in width. R.S.O. 1990, c. H.8, s. 62 (17).

The problem with this law comes in subsection 18:

Penalty

(18) Every person who contravenes subsection (17) is guilty of an offence and on conviction is liable to a fine of not more than $20. R.S.O. 1990, c. H.8, s. 62 (18).

I would like to see the law changed to state that the light must be visible for 150m (500'), and the fine increased to at least $100, preferably $200. The fine for not having a bell is $100, and most bells sell for less then $10, so most people do not want to take the chance, but even a reasonably cheap light is more then $20.