Yep, DHS = Department of Homeland Security. When I saw MAFIAA pop up on Slashdot, and then Ars Technica, it reminded me of JTH's old April Fool's Day joke. Well, somebody took his joke and made it into a Firefox extension. "MAFIAA Fire" that redirects users to the new hosts of piracy sites taken down by ICE. Now DHS, on RIAA/MPAA payroll, wants Mozilla to take it down from AMO. Mozilla told 'em to take a flying leap, and it looks like they're backing down.
"MAFIAA Fire" has a website, and a pretty extensive FAQ, and I didn't see John T. Haller's original MAFIAA page get mentioned, even once, which I thought was pretty disrespectful. But maybe it's for the best pirates aren't calling attention to this site? Still, it was pretty funny.
On a more serious note, I have seen "MAFIAA" referenced in the Ars Technica forums, more frequently in articles about copyright and filesharing news. People there will give due credit when asked about it.