Interesting to see the different points of view here. Firstly we have the 'tabloid readers' who somehow decide to throw in made up statisitics about the number of murders in the US when compared to the whole of Europe. They obviously never considered the Balkans and the nasty little wars that take place there from time to time.
Next we have the gung-ho Texan types with sore cojones from dragging them along the ground with their "I'll leave the flight deck and deal with the drunk". Obviously not a pilot who flies multi crew aircraft then.
Whilst it may appear to the 'overendowed with testosterone ' types that remaining behind a locked cockpit door is a bit sissyish, I presume that most of them are not airline pilots and fail to realise that should their fantasies of a hollywood like overpowering of the drunk fail and they end up getting incapacitated through injury (just read about the guy who got kicked in the nuts) then you have an emergency situation and one poor pilot left to fly a two crew aircraft. On top of that you probably have the medical emergency aspect to contend with too.
Most cabin crew are trained to deal with conflict management and some are even trained in how to overpower and restrain unruly pax. Of course, any of Bin-Liners deciples now know that they only have to board a Texan airliner, have one of them act a bit drunk and they can be sure that one of the flight deck (you know, the John Wayne types who walk bow legged because of the large cojones) will open that door and come out to brandish his machismo and deal with the offender whilst the rest of Bin-Liners gang use the opportunity to its full effect.
