So, basically what it comes down to is "DON'T STEAL COPYRIGHTED MEDIA".
If you don't steal the stuff, then your name should not be amongst the details stolen from ACS.
There is plenty of free porn available legally. I know that there are people who rip off entire websites and then share or even sell the content as if it were their own, selling memberships to copied sites. These people should be named and shamed.
The problem with 4chan is that the evidence being stored by ACS has now been compromised, which may well mean the information cannot be used to prosecute. The question is - what were the 4chan users trying to do?