halavai, you said it. On every cell phone bill it will show all texts, internet, downloads, etc. With just a little reading, you can figure out exactly what your kid is up to.
And azi, what you’re saying is all too true. keep your kid too restricted, and he’ll break out and do anything and everything he wants to. I’ve heard too many of those stories. Better to give him a cell phone, and keep close watch.