8th and made off with an estimated $400,000 in stolen goods. cnn analyst john miller says these are likely crews, some associated with gangs. how would they organize for one hit? >> it's word of mouth, but the electronic version. someone sends out a text message saying we're doing an hit on wednesday, who's in? other people may speak in person. they'll begin to gather. then it's who's going, what vehicles are we using? >> reporter: authorities say there have been at least 170 of these flash mob robberies across the u.s. since fall of 2021. can law enforcement catch up to these perpetrators? miller believes they can with the fbi and marshals able to bring federal charges. >> once you find the organizers of these groups and they start to face federal charges under the hobbs act for organized