You may have seen the stunning surveillance video from the Portland convenience store where several dozen individual swarmed into the facility, grabbed various items from the shelves, and ran out.

Authorities say it's not necessarily new,  but such incidents are quickly spreading across the country.  The Gill Mart Chevron in Portland was the scene of a "ganglike" group of young people who swarmed the store, and while leaving, threatened the employees--even throwing a milk crate.   Police say that at least one in 10 retailers report being the victim of such a robbery.

  Authorities say video cameras, if properly installed and placed, can help significantly in identifying the criminals.  They also say that these youth are using social media to coordinate their attacks.  They say it's the 'gang' mentality applied to flash and dash robberies.   Usually, store personell are so overwhelmed they have no choice but to look out for their safety and cannot attempt to stop the attacks. Store owners often schedule as many as 3 employees in larger cities during evening and late night shifts, but even this added employee presence is ill-equipped to stop such an incident. This is video of the Portland, Oregon incident.