As with some 300 others this has also happened to me. And I buy a lot of stuff over the internet and am VERY VERY careful with regard to opting into things and privacy protection. On June 30, 2005 I purchased tickets on Ticketmaster (a ripoff in and of itself - I might add). When done, I vaguely recall some sort of popup asking me to fillout some questionaire or somesuch nonsense. I am quite certain that I would have summarily dismissed such crap as that.
Today I noticed a $9 charge to my card and upon further checking found it as well on the previous months credit card statement. I called the 800 number and like everyone else here listened to Muzak for 45+ minutes. Finally some troll answered the phone and essentially blew me off telling me that I had deliberately joined, not once, but twice in the same session. Furthermore, NO she would not issue a refund. No amount of complaining on my part swayed her. But she did offer to cancel my "membership" effective today. I am certain that Ticketmaster violated my privacy and provided my CC and other private information to Entertainment.com.
If anyone wants to get a Class Action going on this I'm in!!! This kind of crap is ruining the internet and must be stopped!!