The RIAA, along with the labels they represent, is very willing to take people to court and demands apeloads of money. We all know this and have seen it play it most dramatically in recent cases. Of course, they sure are happy when they win. When they lose, however, it seems they get cold feet when it comes to owning up to the responsibility.
The RIAA dropped a case against Tanya Andersen quite a while ago, prompting her to retaliate and ultimately seek not only a class action suit against them, but compensation for legal fees. The courts agreed with her, and said the RIAA should pay. They are unwilling to do this, however, and are fighting to avoid paying the fees. Even though the fees could be in the hundreds of thousands of dollars, the RIAA feels that since there is still a "chance" she could be guilty, they don't feel justified in paying.
I guess by that logic that since there is a "chance" many of their targeted victims could be innocent, that none of them should have to pay any form of settlement.