Does Microsoft actually license their VFAT patents to all that many small embedded device manufacturers? Most pairs of large companies license each other all their patents in bulk without regard for any specific patent (because caring about specific patents would lead quickly to lengthy and expensive negotiations). For companies that Microsoft doesn't have a cross-licensing agreement with, I'd guess that a lot of them either don't write to VFAT at all or don't write to files with long filenames, because it costs an extra sector write against your file creation performance and you don't generally have useful names to give files anyway. (As far as I can tell, my camera's only able to set up a particular fixed empty directory layout if it doesn't already exist and create files of the form "dscnXXXX.jpg", and I would guess that they have a cross-licensing agreement and still avoid the VFAT hack.) So I wouldn't be surprised if there isn't anybody who's specifically licensed this patent.