Any citizen of the United States, wherever he may be, who, without
authority of the United States, directly or indirectly commences or carries on any
correspondence or intercourse with any foreign government or any officer or
agent thereof, in relation to any disputes or controversies with the United States,
or to defeat the measures of the United States, shall be fined under this title or
imprisoned not more than three years, or both.
This section shall not abridge the right of a citizen to apply, himself or his
agent, to any foreign government or the agents thereof for redress of any injury
which he may have sustained from such government or any of its agents or
subjects.