I remember the shit the happened on u2's vertigo tour - tons of ppl who had been paid up members of the old U2 Propaganda Club got right-royally screwwwwwwed over on presale tix - codes not working, TM crashing, credit cards refused for no reason - the boards were going mental with so much traffic that Larry Mullan jr. actually sent out a personal email to all members apologising for to mess and promising to make sure that it didn;t happen again.
This time around, for the 360 tour, it went far better. They split the membership into three groups - full u2.com members with unbroken, paid up membership got access to the presale first, then the two other groups, all based on how people had been members for.
Here's the interesting thing though, as far as I can remember, the mods at u2.com asked the memebers to watch out for ticket listings on ebay and to post the links on one of the boards. They then had ticketmaster cancel the tickets and/or have ebay drop the listing. Someone can correct me but I think thats how it worked and it I believe it worked pretty well, not perfect, but better than doing fuck all about those fucking scum touts.