Chris

If someone breaches our T&Cs, they get warned. If they do it repeatedly, they get 'banned' - that is, their posting rights are permanently revoked and we actively seek to prevent them from re-registering. What we don't do is attempt to prevent them from accessing all those parts of the site which are publicly viewable without registration.

The fact that a website is published means that the publisher implicitly accepts that certain things may be done with it. The question here is whether the creation of user accounts with additional privileges is analogous to the use of certain lines of code to attempt to control the behviour of other, automated internet systems.

Our membership system requires active human involvement and specific agreement to a set of conditions, in order to gain access to parts of the site that are inaccessible otherwise. I don't see that as being much of a comparison with a line of code that asks a spider or other web cataloguing system not to record certain content when that content is visible and not protected by any password.

Of course, you might then want to argue that the code in question amounts to a password protection against web-crawling systems, and that by ignoring it, the operator of that system is effectively 'hacking' your site. Personally I can't see a judge going for that.