This video went viral a couple days ago and is allegedly from a security camera in a restaurant somewhere in Russia. From a nonverbal perspective, it could have been filmed in London, New York or Tokyo - for there is an extremely common pattern seen here, which like virtually all other body language - assault or otherwise - crosses all cultures and national borders.
This assault is atypical as it involves a large number of attackers as well as it appears to be targeting several people at one table (incidental violence to other nearby individuals in such scenarios is common though and some is seen here). The nonplussed demeanor of some people suggests they are immune because they are either involved or that they "know"/believe that as long as they keep out of the way, they will be spared (implying such activity is frequently witnessed).
Obviously most of these men appear to have ski-masks or similar garb covering their faces. This feature alone of course screams of an imminent attack. Yet the valuable take-home point here is that they're walking in a single-file line. When several individuals are about read to attack, it is extremely common that they will not walk shoulder-to-shoulder, but rather in a line. The pace of the stride in such scenarios is also typically quick - as is seen here. It is difficult to tell, but no firearms appeared to be involved in this incident - in such cases the hands will typically stay inside their pockets until the last moment when the gun is brandished (Therefore in these gun-assault cases, arms will not be swinging - compared with most of the attackers seen in this example). Such swinging arms immediately before the attack implies fists were planned rather than guns or knives.
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