According to information, Microsoft argues that Android violate several patents of their own.
Remember that the Android OS is open source, so it is distributed free and allows developers to build applications without permission. This has achieved a high penetration in the world market.
However, local media report that Samsung could reach a financial settlement with Microsoft, and refer to an agreement with the maker HTC for similar reasons. They are business partners, as markets Samsung mobile phones equipped with the Windows Phone 7, Microsoft.