"Long before this case appeared, the PUBPAT (Public
Patent Foundation ) tried to get the '517 patent, which is the core
patent of the trio, overturned. PUBPAT argued that there had been
"previously unseen prior art showing the patent, ... was obvious
and, as such, should have never been granted." However, in the end,
the Foundation was unable to get the U.S. Patent and Trademark
Office to overturn the patents.
"To astute open-source legal observers, these patents have long
been troubling. By requiring vendors to pay a royalty for their
use, this could make it impossible for free software systems to
read and write to FAT file systems, because their open-source
licenses forbid royalty payments."