what are your feelings about another passenger in this situation "wading in" and doing a little "head-knocking"?
It has been my experience throughout the years that unanswered physical force ENCOURAGES and EMBOLDENS the perpetrator of said force. Citizens that are capable of immediately ending violent attacks should do so imo.
Most groups have a "physical" leader, either formal or informal, that can influence the behavior of the group as a whole, directly or not. When the "physical leader" resorts to force, and is immediately shut down by greater force, this has a dampening effect on the other members of the group because their "big gun" proved to be ineffective. The rest generally become reluctant to engage in physical force.
However, should the "force leader" be met with little to NO resistance, this tends to embolden the actions of the group, and can lead to force beyond the span of control / intent of the group.
Being able to identify and neutralize these types of individuals can go a long way to checking the actions of a potentially violent and lethal group of individuals. The kid in the video did not do it, and his lack of action emboldened not only the initial attacker, but the group as a whole. Had the kid applied a well placed throat punch to the FIRST individual that attacked him, the rest of those females would not have dared to touch him, or his girlfriend, further.
It is 2010, almost 2011. The whole "don't hit a female" / honor thing is DEAD. Females need to learn what smart males learn by the age of 10, and that is, if you intend on resorting to violence, you better have the ability to back it up, or you WILL get your arse kicked. NO pass for violence, for either male OR female. THAT'S equality.