so too does the collateral damage. but cancun becoming an unsafe place for tourists, those ideas seem premature. matt rivers, cnn, mexico city. and joining me now is the head of security research programs at the center for u.s./mexican studies at the university of california, san diego. she joins me from mexico city. i guess mexico, violence there isn't new, but it does seem extraordinary places are going on like in cancun. it shows how fearless the gangs are. why is this happening? >> thank you for having me. when we see stories like these, the initial reaction is to think that it's related to the drug trade. certainly there's a component that is linked to the elicit activity of drug affectctivity.