The way web services handle account information, and allow (or disallow) account deletion, and respect their user's privacy is certainly a big part of the User Experience.
As an experiment, I'm attempting to delete several accounts I don't use. Some web services offer a "Delete account" action, but others don't, or make it very difficult. I've had to personally contact some for account deletion, and they refuse, not even allowing a username change.
If you read through the Agreements, you'll notice that they state that information is kept private from third parties, however, your profile is easily searchable in Google and other search engines, which are third parties. Moreover, every last one of the clauses is then made null by a "I acknowledge that the Company has exclusive rights to all the information and software located at the Service pages."
Correct me if I'm wrong, but isn't this a very bad malpractice? Shouldn't a User be freely allowed to remove his account and information from a service if he wanted, no matter what kind of complex agreement you've accepted? Shouldn't be this a basic "online human right"?
As a part of my experiment, I'd like to know what is the true accepted and jurisdictional aspect of this matter. Which organizations and laws prevent this kind of behaviour on online services?