For example, in the United States Code, 18 U.S.C. § 2385, "Advocating overthrow of Government by force or violence": Whoever knowingly or willfully advocates, abets, advises, or teaches the duty, necessity, desirability, or propriety of overthrowing or destroying the government of the United States or the government of any State, Territory, District or Possession thereof, or the government of any political subdivision therein, by force or violence, or by the assassination of any officer of any such government; or Whoever, with intent to cause the overthrow or destruction of any such government, prints, publishes, edits, issues, circulates, sells, distributes, or publicly displays any written or printed matter advocating, advising, or teaching the duty, necessity, desirability, or propriety of overthrowing or destroying any government in the United States by force or violence, or attempts to do so; or Whoever organizes or helps or attempts to organize any society, group, or assembly of persons who teach, advocate, or encourage the overthrow or destruction of any such government by force or violence; or becomes or is a member of, or affiliates with, any such society, group, or assembly of persons, knowing the purposes thereofâ Shall be fined under this title or imprisoned not more than twenty years, or both, and shall be ineligible for employment by the United States or any department or agency thereof, for the five years next following his conviction.
I don't recall the complete circumstances but Ayres was able to reach some agreement with the government not to prosecute him over his Weatherman activities. I remember that it was some bogus bull shit agreement the government agreed to. You could probably find the circumstances with a google search unless Obama has had it cleaned off the Internet. (I've noticed incriminating facts about Obama and his friends have been dissappearing off the Internet over the last few years.)