Datel, a company selling memory units for Xbox 360 consoles, filed an antitrust suit against Microsoft for blocking unauthorized third party memory units. Microsoft claims innocence, as the block is meant to reduce cheating on Xbox Live, not reduce competition.
Datel maintains that Microsoft is "disabling or erecting technological barriers to Datel accessories" and thereby favoring its own products. For reference, Microsoft's 512MB memory unit is about $30, while a 2GB version from Datel is $40. Sounds like it might be worth supporting the little guy in this one. [Techflash]
Sorry about the previous typo, it's 512MB for $30 on the Microsoft memory unit, not 12MB.