BoingBoing: New iPods Reengineered to Block Synching with
Linux
"The latest iPods have a cryptographic 'checksum' in their song
databases that prevents third-party applications from synching with
the portable music players. This means that iPods can no longer be
used with operating systems where iTunes doesn't exist--like Linux,
where gtkpod and Amarok are common free tools used by iPod owners
to load their players.
"Notice that this has nothing to do with piracy--this is about
Apple limiting the choices available to people who buy their iPod
hardware..."