More moreover the use of children by criminal organizations dates to the turn of century (not this one, the previous one) amazingly enough the reason have stayed the same, society tends to be more lenient on children and in modern society you have the dual benefit of an able young body (14-18) that it's still considered; legally, a minor. Plus they are very impressionable and easy to manipulate.
I'm a little bewildered by this thread; maybe because of the country difference, but this has been a problem for some time now. Specially since a lot of the gang violence related crimes are committed by youth.