My impression is that the copyright trolls use the archives to indicate how long an infringement might have existed.
That's after a "live" version has already been found online.
They're already chasing so many presently existing infringements that a lawsuit for an old infringement is unlikely.
Many places have provisions in law that a lawsuit must be timely.
That is, a lawsuit must be brought within a time that the plaintiff could have and should have known of the offending situation.
In any case, such a suit would be very weak. The work of these archives tends to be rather "spotty". There's no guarantee of accuracy.
You could simply say that the offending content on the archive was never part of your site, and it would be up to the other party to prove it.
Matt's right that people can sue for any reason, and this leads to abuse.
In our society, threats of lawsuits occur so often that these threats carry less and less weight over time.
I once had a job offer; the money was actually good, but the employment contract stated that they'll sue the employee in a certain situation.
Of course, that's a difficult thing to pull off. But, it exposed the company workplace as "toxic". Needless to say, I took my talents elsewhere.
buddhapi's right about the meta-tag. But, I think that domaintools ignores those tags, as they're making money serving the copyright trolls these days.
If anyone has the IP address(es) of the domaintools robot spider, I'd like to know.
I want to add those to my .htaccess file, thereby blocking access to my site.
If your web server uses Apache, you can make an .htacess file, too.
I often wonder if we'll see more court "summary judgments" in the future.
If the courts ever become clogged with copyright cases, the system could save a lot of time by simply dismissing cases immediately wherein there's no proof of copyright ownership.
S.G.