Flash to Pass

[AWD Chaser]

When I was much younger learning to drive, I was taught to flash a car (with my headlights) from behind if I wanted them to move over (into the lane beside them) as this was more curtious then leaning on the horn.

Today, I was driving home in the rain and got stuck behind someone doing 60 in an 80 zone sitting in the right lane. I know the road, and there wasn't a right turn for at least 5 k's so rather then zooming up the left side of them, I just gave them a quick flash of the headlights which they responded to by giving me the bird! So I ended up having to duck up beside them and pass them onthe left ... and I made sure I gave her a curtious bird in return.

My question is: Does anyone still use Flash to Pass, or have you even heard of it? And given todays crackdown on stupid laws, is it even legal?