Red Bull doesn't sell hats to the public because they want to attract athletes by giving them limited apparel. I believe Red Bull has the right to sue companies who infringe on their copyright laws. Taking bootleg hats off kids heads is a little ridiculous; calling them out = I don't see whats wrong with it.
If people really wanted to support Red Bull they wouldn't buy fake hats. It hurts the company because it makes it harder to attract the athletes that you guys love. Why would Sammy want to rock a hat that everyone else has.
As for the moral issue, I believe that no one should support illegal bootleg anything (but that is a whole other thread).
And as for the cool issue, well thats personal prefrence. I would definitly rock an official Red Bull hat if I could get my hands on one, but now that so many people are wearing fakes its just pointless. And when people asked about it, I would just say that Red Bull is a sick company that sells gross tasting energy drinks.