Yeah they are, if you are RIGHT in front of them. Not even close to blinding from 20m away.
I have far more experience than you do with them, if I am guessing. You've posted twice that "cops use them". Well guess what, not only am I a Marine who like I said have used such tac lights and "lasers" (PEQ15/14's) in two combat deployments, but I am also a cop. I have done countless hours on MOUNT training, and have been on the receiving end of a surefire many times. Plus, Marines like to prank each other a lot, and do stupid things when we have down time. I've been hit in the eyes many times with a tac light. I have plenty of Surefires, and the same kind that BF3 uses.
The simple
fact is, it's much too exaggerated to be even close to realistic. And people (re:douche bags) use them to blind people in day light on purpose. And the PEQ won't to it unless it is exactly in your eye, not even an inch off. There is even one such person who admitted to using it for such a reason a few posts before me. Just because it's in the game, doesn't mean you should use it. Just like the one shot/kill smoke 40mm. People spammed it all over till it got patched out.
You can see my PEQ, and my Surefire is on the rail on the other side of my weapon. Don't feel like digging to find a pic with it exposed. Don't mind the pot field behind me, it's of no consequence...
Yeah some people may think it's nit picky, I just find it stupid that it is so over used, and exaggerated in the game. It's the worse thing I hate about the game, and the fact that I have to keep selecting my server settings all the time. It unchecks my regions, game types, and maps I selected every few days. Pisses me off also.