I have heard QF, JQ and VA share their no fly lists and they are reciprocated on each airline. It was a fairly recent initiative (ie. 3-4 years from memory). However they don't last that long, maybe 12 months for the 'non-airlines' and if the misdemeanour is bad enough, a lifetime ban for the airline the offence it took place on. Should be more of it this enfocement though, especially for drunken idiots that have no regard for the rules, let alone the rules in a pressurised aluminium tube.