Clearly not been to any town at night when the clubs kick out, a regular sight near me is young men throwing arms up in the air to appear larger than the other young men whilst shouting "come on the you c**t" to some random person who is either to drunk to respond or just don't care.

Also the widening of arms which is perceived as friendly to most people takes on a sinister alternative meaning outside of Frank's kebabs & chicken at 2am, again, to look larger and more intimidating to other young lads whilst shouting "oy" to whoever bumped into them and dropped their last chicken wing.

It's all very dependent on where you live as to what these actions mean but to me, if I see someone raise their hands I'm gonna go on defense and keep an eye out rather than think they are peaceful.