When you are on some abuse list from an ISP you propably know these kind of things: you get copyright/intelectual property/whatever infringement alerts from various institutions every now and then. I won't try to guess if they themself are actually downloading all the data to verify the content, or maybe even put it into the peer to peer networks to see who is going to download it.
Nevertheless, sometimes there are quite funny companies with their alerts out there. One of those is the ESA—the Entertainment Software Association. The following is an excerpt of one of their mails stripped down to the relevant parts:
-----BEGIN PGP SIGNED MESSAGE-----
[key 0x9E9658B85A10FEEC unavailable]
ESA believes that its members' rights in such entertainment software products
are entitled to the full protection of the intellectual property law as well as
other relevant laws of your country.
Please inform us whether you will remove or disable access to the Infringing
Material as requested.
Given that they say in their headers that they don't want reply, both in the From and Reply-To, they still request information about the actions taken in their mail body. Yes, there is a different mail address listed in the body too, though that's not how mail programs work, do they...
Then for added authentity they pgp signed their message. Though, I wasn't able to find a server on which this key is available, and there is no hint in the mail where to get it from. Quite trustworthy, isn't it. It adds that the whole mail says that it's a template, though states that they are "entitled to the full protection of [...] relevant laws of your country". One starts to wonder if they are at least remotely aware to which countries they are mailing...
P.S.: On a side note, their second listed MX record doesn't seem to feel responsible for the domain—it simply sends you a 551 5.7.1 relaying denied when one would try to deliver there. Adds to the impression that the ESA is nothing but entertaining...