reporter: in minnesota, more organized smash-and-grab robberies at two separate best buy stores last friday. tvs, tablets, and hover boards stolen by brazen mobs mimicking the thieves that hit an apple store near san francisco. grabbing and running off with expensive electronics. the robberies adding to a recent spate of similar large-scale thefts hitting big retailers and designer stores in major cities last week, including this louis vuitton store in san francisco. we have been seeing this wave of people invading stores by and large numbers. there is no way, in my mind, that we can have a situation where 20, you know, up to 80 people can invade a store or series of stores and there not be some communications and some organization. reporter: on friday, a home depot near los angeles was robbed by as many as ten thieves who stole sledge hammers, crow bars, and other tools, like those used in smash-and-grab thefts. four men have been arrested in that robbery. on saturday, a securit