EFF urged a federal court to block Microsoft Corporation’s attempt to misuse copyright law to thwart a competitor offering memory cards for the Xbox gaming system. Microsoft claims that Xbox users violate U.S. federal law — the Digital Millennium Copyright Act (DMCA) — if they use third-party cards memory cards, such as those produced by Datel Holdings. If Microsoft were to prevail on this point, it could give the software giant the ability to use the DMCA to prevent competitors from selling Xbox-compatible accessories, like memory cards, controllers, and headsets. Such a ruling would have wide-ranging ramifications for hundreds of other consumer products.