In March 2003, SCO filed suit against IBM alleging(saying) that IBM's contributions to some free software, including FSF's GNU, violated SCO's rights. While FSF was never a party to the lawsuit, FSF was subpoenaed on November 5, 2003. During 2003 and 2004, FSF put a lot of advocacy effort into responding to the lawsuit and removing its negative impact on the adoption and promotion of free software.