I try (if I have time myself to do it without hitting someone and am just in front a mess) to “wake people up” a bit by rapidly tapping the brakes before hitting them hard (to hopefully make my brake lights flash).
I feel like I looked into that once upon a time and it was illegal in my state (Ohio).
I have seen something like that though, at times it’s a bit too much IMO. I’ve seen some that trigger for pretty gentle braking so there’s just a strobe light distraction in front of you over relatively minor things.