sledge hammers and crow bars, the same kind of tools used in a number of smash and grab robberies this month. professor charisse cubern is with us. thank you so much for joining us. almost every day we're getting reports of new attacks by these flash mob thieves. what we're seeing, it seems like scenes from some sort of dystopian movie. what's behind all of this? >> we're still trying to get a handle on exactly what's going on with these types of crimes. on the one hand, the places that they're occurring, cities like los angeles and san francisco, at least in california, are places that have seen lots of retail thefts over the years, and in fact, rank in the top ten. on the other hand, as you mentioned, they're quite distinct. they're very unique. these are involving many, many individuals that are highly organized, using social media in many cases to get that