I've considered mounting such a beast on my handlebars, just so I reciprocate cyclists who blind me. But I'm guessing such a thing wouldn't be entirely legal.
Some countries have very specific standards for bike lights; others have none. Most jurisdictions have a crime like "reckless endangerment" though, and intentionally shining bright lights into a cyclist's eyes could qualify.
[0] Most flashlights that advertise numbers like this are lying, but a few aren't
[1] This does present a risk of impairing the driver's vision