Where are you getting this from? If you own a site, you own it; it's your property, and you have a right to decide who can use it and who can't, and you have the right to change your mind whenever you please. Just as,if you let someone into your house, but then their behavior becomes intolerable, you can kick them out; they can't argue that, since you let them in once, they now have irrevocable permission to stay there forever.
3Taps made a similar argument in the court case: they argued that if Craigslist allows the world to access craigslist.org, it can't then turn around and revoke access for a specific person or entity. But that conclusion is obviously too strong: it would not only prevent people from selectively banning, it would also prevent sites from fighting denial of service attacks, since fighting those often involves banning suspect IP addresses.
I think I may have made myself unclear. I'm not saying you don't have the right to ban someone from accessing your server. Of course you do.
I support the right of a site owner to try to prevent a person from accessing his site. But I don't support the right to make it illegal for someone to access this person's site if he's making it publicly available.
I don't support the right to make it illegal for someone to access this person's site if he's making it publicly available.
Even if I've sent the person a C&D letter? Accessing someone's site after they've explicitly given you legal notice not to is basically the online equivalent of trespassing.
3Taps made a similar argument in the court case: they argued that if Craigslist allows the world to access craigslist.org, it can't then turn around and revoke access for a specific person or entity. But that conclusion is obviously too strong: it would not only prevent people from selectively banning, it would also prevent sites from fighting denial of service attacks, since fighting those often involves banning suspect IP addresses.