In October 2009, Microsoft released an update for the Xbox 360 which intentionally blocked 3rd-party (non-Microsoft) memory cards from working with the game console. UK-based Datel Design & Development, maker of 3rd party memory cards for the Xbox 360, then sued Microsoft, claiming it was engaging in anti-competitive practices. Datel sold 2GB memory cards for as low as 40 USD, whereas Microsoft's own 512MB cards go for about 30 USD, and on top of that, Datel used simple microSD cards, so you could backup data on your PC.
"Microsoft's purpose in disabling Datel's memory cards is to prevent consumers from choosing a Datel product that offers far better value for the price," Datel said November 2009, "There is no benefit to consumers from Microsoft's decision to target and disable Datel's memory cards. To the contrary, Microsoft's actions will leave approximately 50000 consumers with useless memory cards and (without the ability to access their data on the cards), forestall innovation, and deprive future consumers of the benefits of competition."
In the lawsuit, Datel argues that Microsoft monopolises the market for "Multiplayer Online Dedicated Gaming Systems", but it only gets there by stating that the Nintendo Wii is not part of that market, which is an arbitrary stretch. In its motion to dismiss, Microsoft correctly argues that not only should the Wii be added to that market, but also the PSP and Nintendo DS.
On top of that, Redmond argues that if Apple is allowed to block clone makers, Microsoft should be allowed to block third party accessories from working with the Xbox 360. They argue that the Xbox 360 comes with a software license that authorises Microsoft to disable unauthorised accessories, much in the same way Mac OS X comes with an SLA which prohibits you from installing it on non-Apple labelled computers.
"Xbox 360 purchasers knowingly and voluntarily gave Microsoft the right to prohibit the use of unauthorized accessories," Microsoft states, "Each Xbox 360 comes packaged with a software license requiring consumers to agree that the Xbox 360 software can be used only with Microsoft authorized accessories."
I find it incredibly hilarious that out of all companies in the world, Microsoft is the one to use the Psystar case to defend its own anti-consumer practices. This also happens to be the millionth nail in the coffin of the idiotic myth, propagated by Mac fans and Groklaw, that Microsoft is behind Psystar.
In any case, this is the world many Apple fans advocate. A world wherein your own products, for which you paid good money, get broken arbitrarily by manufacturers because they don't like competition. Like I said - it's a snowball effect. It starts with Apple blocking clone makers, but it will end with you not having any control whatsoever over your hard and software.