I just emailed this to Ticketmaster (legal@ticketmaster.com), and I encourage you to do something similar:

To whom it may concern:

I disapprove of the following clause on my user info page (especially the bolded section):

By purchasing a ticket to an event, or completing this registration form in order to be able to purchase a ticket to an event or to bid in an auction, you indicate that you consent to Ticketmaster sharing your e-mail address and other information (e.g., venues, teams, artists' representatives and fan clubs, promoters and leagues), and that you consent to those involved in the event using your information to contact you by e-mail or other means to send you marketing or other messages or using or disclosing your information in other ways. Please contact them directly to learn about their policies.

I believe you need to clearly specify to the artists, venues, teams, etc what is proper use of my email address. They have no right to disclose my email address to a third party. I believe you should work with them to define what is appropriate use of my address (notification of a venue change, show cancellation, one time invitation to the fan club, etc) instead of just passing the buck. I also believe I should be able to opt out of the sharing of my address with a party other than Ticketmaster.

This is completely unacceptable from a privacy standpoint.