According to information obtained by SJD the accusations are not made up. This means that the IP-addresses were indeed “caught” sharing the files listed in the letter. However, it is a mystery how the “Internet Copyright Law Enforcement Agency” obtained the home addresses of the subscribers.
It was only a matter of time before these kind scams surfaced. The outfit in question is here. Fearful of real life charges of real crimes involving interstate commerce probably convinced them to publish this on their site:
Effective immediately, the Internet Copyright Law Enforcement Agency has ceased operations. Please disregard any notices you received from us, and please do not send us any payments.