Several recent studies suggest that bicycle lighting is yet another example of the motoring majority imposing faux-safety-prophylaxis on the cycling minority.
Hat tip: Alan 1.0 at bike portland.The German Cyclists’ Federation ADFC has studied the subject of bicycle accidents at dusk and in the dark in Europe…
...This suggests that the different rules have only a marginal impact on the safety of bicycle traffic in the dark. Only a small number of nighttime accidents can be clearly attributed to the lack of lights: Other major risk factors are driving or riding under the influence of alcohol, higher driving speeds on empty roads at night and impaired night vision especially in older drivers.
BikePortland Podcast: The Great Blinking Light Debate (and more) - BikePortland.org
See also a Dutch study:
And this citation is dedicated to acidfast7:
StVZO §67: Lichtechnische Einrichtungen an Fahrrädern
It turns out that even the dynamo mad germans have decided that cheap battery-powered led lighting is OK!