Look up the iata guide lines on how to handle unruly pax :
http://www.iata.org/whatwedo/safety/...st-Edition.pdf
I understand that it is ALL UNDER THE PIC's ultimate authority on how to address the situation. Powers and Immunities bestowed upon them by the Tokyo Convention 1963 to assess and deal effectively with unruly passenger behavior on board.
Also, look up if the countries you are flying for participate in the Convention.