Well, thanks for bringing up these examples,
jyl. I sure do give personal safety highest priority. Especially in the case of right turns I think it's a good strategy to illuminate the cockpits from behind, also the rear view mirror must be completely white -> would be hard not to notice a cyclists approaching.
Another big difference between Germany and US might be the width of the roads. I rarely see those multilanes wide roads here, normally they are much narrower, and i often take the lane, so it's easier to get the oncoming traffic close enough to make it blind. In US it probably happens less often.
Like i already replied to cyccommute, if people know what they are doing and if it's gonna improve their personal safety without compromising the safety of others, perhaps adding only a bit of minor discomfort, then i have absolutely nothing against it. I started city commuting not in Germany but Russia, where it's much more of a mess and it made me doubt the competence of every single motorist. Those stong lights were not there yet, so i had to rely on the weak once. Probably now i would have resolved to using the magicshines just like you describe, i know people are doing it there as well.
In general, I think - guess, really - that sort of aggressive light usage wouldn't be normal in Germany. I'm guessing that because, as far as I know, you're not even permitted to have blinking lights on a German bicycle.
Right, i don't think it would be normal. Even if motorists and cyclists do not share the road they still stay pretty close, all of them, both directions. I find that it's often quite packed, you will find a pedestrian sidewalk, bike paths and a two lane road all within few meters. Hence my worry about blinding the oncoming commuters and pedestrians.
PS. True, blinkies aren't allowed. Though many use them anyway, our childrens trailer has blinkies, in addition to steady lights on parents bicycles/rucksacks.