Maybe they shouldn't be doing 1.2 million dollars worth of drugs at concerts.
I don't understand how they could confiscate cash though, unless it was from people caught clearly in the act of buying drugs, there's no proof that it was going to purchase drugs. That could have very well been for merchandise or gas money home if they made a trek.
I don't have any sympathy for the people that thought it would be a good idea to bring thousands of dollars of acid to a Phish concert. I would probably need to do thousands dollars worth of acid to find a Phish concert enjoyable though.