The Posse Comitatus Act of 1878

We are sure to hear more about this after President Bush speaks tonight, so here's a link to the Wikipedia site for The Posse Comitatus Act:

Sec. 1385. - Use of Army and Air Force as posse comitatus

Whoever, except in cases and under circumstances expressly authorized by the Constitution or Act of Congress, willfully uses any part of the Army or the Air Force as a posse comitatus or otherwise to execute the laws shall be fined under this title or imprisoned not more than two years, or both.