Licensing and patent issues

A large number of different organizations have claimed ownership of patents necessary to implement MP3 (decoding and/or encoding). These different claims have led to a number of legal actions, and legal threats, from a variety of sources, resulting in uncertainty about what is necessary to legally create products with MP3 support in countries that permit software patents.
The various patents claimed to cover MP3 by different patent-holders have many different expiration dates, ranging from 2007 to 2017 in the U.S.
Thomson Consumer Electronics claims to control MP3 licensing of the MPEG-1/2 Layer 3 patents in many countries, including the United States, Japan, Canada and EU countries. Thomson has been actively enforcing these patents.
For current information about Fraunhofer IIS and Thomson's patent portfolio and licensing terms and fees see their website mp3licensing.com. MP3 license revenues generated ca. 100 million Euro revenue to the Fraunhofer Society in 2005.
Reference : http://en.wikipedia.org/wiki/Mp3