This is a little dated, but Ken White has a mega-update on the Prenda Law case he has been following.
The ins and outs of this case are complicated beyond belief (likely purposefully by the key players in a bid to obfuscate what they were doing), but the basic facts appear to point to this: Prenda and a series of related entities were buying copyrights to porn, uploading electronic versions of these videos to known pirating sites, and then suing folks who downloaded the files (knowing that most folks, embarrassed that they downloaded "Chubby Nurses in Heat" or whatever, will fold and pay a settlement rather than get in a public legal fight). One reason for the complexity and obfuscation is that the porn companies (AF holdings and many other shells) have to pretend on the one hand that they didn't upload the files themselves in a "honeypot" operation, and on the other hand that they have no relation to Prenda Law. By the way, the scheme apparently brought in about $2 million in 2012 alone of which at least two thirds, and likely more, ended up in the pockets of the key principles.
What makes the case so fun to read about is the just idiotic antics and evasions by the key players, the hapless lawyers, the "dog ate my homework" excuses in front of senior Federal judges, etc. All this combined with an arrogance among the principles that could be a case study in the Wikipedia entry on Dunning-Kruger effect. The bad guys remind me of nothing so much as the William Macy character in Fargo. This, for example, is a hilarious article with examples of one principle after another offering absurd testimony to various Courts.
Since the post above, Ken has an update here.