Apple has also voiced concerns that Ogg Theora may be encumbered by unknown patents. That risk isn’t significant to Mozilla and Opera, both of whom could simply abandon the format for something else in the same way that the web temporarily abandoned commercial support for GIF after Unisys tried to sue everyone for using it. However, for a company like Apple that has built a business that requires selling media content and supporting hardware acceleration in mobile devices, it’s not possible to randomly drop a codec technology when a submarine patent threat appears. Apple also has a bankroll to attract patent trolls that Mozilla and Opera both lack.
http://news.ycombinator.com/item?id=691844