Whoever willfully transports in interstate or foreign commerce any person who is employed or is to be employed for the purpose of obstructing or interfering by force or threats with
(1) peaceful picketing by employees during any labor controversy affecting wages, hours, or conditions of labor, or
(2) the exercise by employees of any of the rights of self-organization or collective bargaining; or
Whoever is knowingly transported or travels in interstate or foreign commerce for any of the purposes enumerated in this section Shall be fined under this title or imprisoned not more than two years, or both. This section shall not apply to common carriers.