So many legal and ethical issues here. I can't believe this is IRB-approved. Teens sending nude photos alone could make that database legally toxic.
And then there's the ethical issue of monitoring those who have not consented to be part of the study, but are friends with those who have. When a friend texted one participant about selling drugs, he responded, “Hey, be careful, the BlackBerry people are watching, but don’t worry, they won’t tell anyone.”