I agree, this is very annoying and can be dangerous at times. When I was younger I always felt like I just must retaliate in some way against these morons. Give them a taste of their own medicine.

Now though I just let those offenders behind me pass and only occasionally do I give them my high beams when they are in front of me. The oncoming morons, I flash once or twice and I have learned to not look into the lights but instead focus on right edge of the road.