US deals with disposal of 9/11 hijacker remains

A recent article on CNN.com raised an interesting question: what should the FBI/ US govt do with the 9 sets of remains believed to be
the hijackers of 9/11? No families or foreign governments have yet
requested their return. Should the US offer to inter them with some sort of dignity, toss them in a secret mass grave, or dispose of them in a manner that is deliberately offensive to their Islamic beliefs? Maybe we could cremate them and put them in a corner of the basement of the Smithsonian? They are, after all, some of the most
hated individuals in American history, though ironically, I don't think anyone here can even name one of them from memory.