1a) Exactly.
1b) They are still using Craiglist's site by interacting with the cached copied of Craiglist's site. I don't know how clearer I can make that. The only way they would not be using the Craiglist site is if they used another listing service altogether.
2) Legally, Righthaven did not own* the rights in question, and that is why the Colorado court kicked out their lawsuits. The court concluded that Righthaven merely owned the right to enforce the copyright because it had granted all the actual exploitation rights back to the newspapers. In other words, Righthaven's "ownership" was illusory and intended solely for the purpose of given them standing to sue. Unfortunately (and I do not know how Righthaven missed this), it has been longstanding doctrine in IP Law that a transfer of all exclusive rights to an IP constitutes an actual transfer of the ownership of the IP (litigation rights are not considered rights in this context).
3b) They are accessing the cached copy. They admit as much. A duplicate is the same as the original, for copyright purposes.
3b) Posters license Craiglist to use their content. They do not license anyone else to use their content. Padmapper is thus an unlicensed user. This can constitute tortious interference in many states because it interferes with Craiglist's ability to full exploit their license.
If Padmapper was using a competitor of Craiglist that the poster had also posted to, there would not be any problems. But Padmapper is using Craiglist's own service, and that factual distinction matters.
4) I don't know how to say this more clearly: you are misunderstanding the legal holding of the Righthaven opinion and how the IP law works in the U.S. It is probably an honest mistake, since IP law adopts a lot of physical property concepts that most techies instinctively reject.
2) Legally, Righthaven did not own* the rights in question, and that is why the Colorado court kicked out their lawsuits. The court concluded that Righthaven merely owned the right to enforce the copyright because it had granted all the actual exploitation rights back to the newspapers. In other words, Righthaven's "ownership" was illusory and intended solely for the purpose of given them standing to sue. Unfortunately (and I do not know how Righthaven missed this), it has been longstanding doctrine in IP Law that a transfer of all exclusive rights to an IP constitutes an actual transfer of the ownership of the IP (litigation rights are not considered rights in this context).
3b) They are accessing the cached copy. They admit as much. A duplicate is the same as the original, for copyright purposes.
3b) Posters license Craiglist to use their content. They do not license anyone else to use their content. Padmapper is thus an unlicensed user. This can constitute tortious interference in many states because it interferes with Craiglist's ability to full exploit their license.
If Padmapper was using a competitor of Craiglist that the poster had also posted to, there would not be any problems. But Padmapper is using Craiglist's own service, and that factual distinction matters.
4) I don't know how to say this more clearly: you are misunderstanding the legal holding of the Righthaven opinion and how the IP law works in the U.S. It is probably an honest mistake, since IP law adopts a lot of physical property concepts that most techies instinctively reject.