Originally Posted by
ESpen36
Furthermore, as noted upthread, USA-based airlines are private companies and can decide to prohibit whatever they want aboard their aircraft, within the confines of the law. If AA hires contract security and instructs them to prohibit salt in carry-on bags, all you can do is write to AA and inquire about the policy.
TSA is not contract security and isn't hired by the airline. They are an agency of the federal government.