Motorola had the patents before the 360 was released (probably before the 360 was in development...) But Microsoft either didn't care or the developers thought Microsoft had already acquired the rights. (Or possibly both.)
As for how Motorola found out? My guess is that they probably reverse-engineered a 360 or were in the process of doing a new system/app or something for it. (Like on some phones you can turn your TV on with your phone, so this way you could use your android based motorola phone to turn on your Xbox/access xbox live, etc...)
In a new twist of the story though it looks like the 360 could also end up banned in the USA too. source
Though for now the Xbox is still allowed to be sold in Germany due to a US interjection.
So thoughts on this new twist?