Ban games, social networking and chatrooms for under 16 year olds. They will soon start exploring graphics packages, fiddling with code, html, php etc. Simples.
My Amstrad 1640 did not play any games, other than perhaps worms, no not the fun worms, worms worms. As such I learned how to use dos properly, set up networks, customise bulletin board systems, started learning basic C and C++. If I had facebook to waste my time on no doubt would have done none of the above.