Last time I saw Radiohead we had to present the credit card used to purchase the ticket from the original vendor. Bam, problem solved.
Radiohead = progressive
U2 = regressive
Yeah, but you have to listen to Radiohead once you get there, so there's that.
As long as TM has no problem selling the tickets, the truth of the matter is they don't care who is doing the buying. All artists can do is make it difficult on scalpers by demanding TM try to battle bots, fanclub presales, randon drawing, waiting rooms (like Prince did and Radiohead did last week), etc. It is exactly like protecting your house from thieves. All you can do is make it more trouble than they want to put in and hope they go away. If they want in your house, they are going to find a way.