I believe the technical term for what these black hole lists are doing is "secondary boycott". I believe that is an illegal activity in the US. So this suit will be interesting to watch.
http://www.legal-explanations.com/definitions/secondary-boycott.htm
Secondary boycotts are in fact illegal in many countries, including the US..
However, unless I'm missing something it's a bit of a stretch to consider spamcop as generating a secondary boycott based on their practice sending complaints to upstream providers.
To be a secondary boycott spamcop would be having to institute a boycott against the upstream providers, inflicting real financial damage upon them as pressure to get their downstream to disconnect the spammers. Merely notifying them of the problem, and even harassing them about it, isn't a boycott.
In this sense, SPEWS would be much closer to secondary boycott than anything else out there, since they have the practice of directly issuing boycotts against the spammers, and eventually spread their boycott to the entire ISP. In this case you *might* be able to argue that a real boycott exists against both companies when the dispute really lies with the spammer. However, IMO, that's a stretch too.
