I don't think you're paranoid. This could very well be true and there is no way a computer non-whizz kid like me could figure out to verify if this were true.
I think that I read something about this here a while ago.
And to add to why it's bad, try thinking of all those people on dial up connections (poor LOTR for example) who patiently wait for the download to finish, only to discover that it's not even a good file. They would (rightfully so, IMO) get frustrated at this and decide, probably after many failed attempts, that it just isn't worth the pain and quit. Result? Less users=less stuff to dld=bad for the network. And don't even think that "Sure, but it's only the case of dial-up people, so it would only make the network faster, right?". Hell no. How many can afford a T1 line? And besides, even a fast Cable connection user would get frustrated if he couldn't get a decent file out of the network.
This is all RIAA-type organisations' plot to discourage people from sharing, if you ask me. And if you add to that people who just refuse to share because they (wrongly) think that it can cause them to catch RIAA's attention, then the network is good for the trash bin.
Anyway, just block these IP adresses through Options. Even if they weren't anti-filesharing organisations but simple users, then its good riddance to them. Serves them right for sharing such files.

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