let's head round the world with zain vergee. she's reporting live from london. ng, zain. >> reporter: good morning, carol. this is a disturbing new strategy and basically it's coming out of the fact that a lot of these cartels think they can give a minimal amount of money to teens and they'll take it, something like $50 for an operation to get them involved in something like that. and also, the laws are more lenient with minors. so that's become attractive as well. what happened earlier this month actually was that a 12-year-old boy was caught in a stolen truck with something like 800 pounds of marijuana. that just gives you an idea of how young the people they're going for are now. here's what the former u.s. drug czar had to say about this development. >> the dominant criminal enterprise in the united states, more than 260 cities, i was just in portland, oregon, talking to their police department, is elements of mexican cartels. they're moving hundreds of metric tons of cocaine, heroin, methamphetamine, ecstasy, marijuana across that border. >> the u.s. border