Forget about RMS. Thomson which holds the rights to the fraunhoffer institute patents for MP3 could go after u.
Then they would be going after a number of other GNU packages too.
http://www.mp3licensing.com/royalty/ to count your potential liability. Completely RAND u know. Do not take licensing and patent issues lightly. They can impair your life. Especially since the closed software companies are scrapping the barrel bottom for ideas and money.
I know that. That is why I asked the GNU people. But, there are many GNU packages which are flaunting MP3 support. Is this not strange? Moreover these patents are very strangely worded. eg., the LZW and GIF patents prohobit you from making programs that encode pictures in GIF, but there is no restriction on decoding them; I heard although MP3 is patented the ID3 tags are not. In fact my only requirement is reading the tags.
Now dont claim that you know more about patents than Dr. Richard M. Stallman, and Prof. Eben Moglen put together.
Cheers, Debarshi