If the FBI 'joins the dots' by connecting Pirate Bay uploader 'sharkmp4' and porn producer Ingenuity13 to Prenda (which seems pretty likely), then Prenda's whole business model looks very different.
They claim to be acting on behalf of Ingenuity13 to defend Ingenuity13 against copyright infringement started by sharkmp4... which would be legal, if they were not taking a blunderbuss approach to sending out accusations to people who are innocent but would rather pay up than go to court.
If however, Prenda, Ingenuity13 and sharkmp4 are one entity, they actually set just up a honeypot on their own behalf, and all the downloads were actually legal (because the copyright holder chose to share the files), all the accusations were false (and actionable), every penny of revenue they made was fraud, and they have been lying to more courts than most other corrupt or racketeering organisations even get to see the inside of. This is so illegal on so many levels that they'll pretty much end up not being sentenced by a court to life imprisonment, but simply dying of old age standing in the dock while the list of charges is still being read out.