In our household, we lump TV, internet, DSI, etc.. together and called electronic time. My DD8 and DD11 are allowed 1 hour of electronic time per day (during weekday) after their homework. Nowadays, they play minecraft whenever they can and rarely watch TV. If they miss homework or house chores or bad behavior, they may lose their privilege upto 2 weeks.

They took up better hobby like origami when they were not allowed to use electronics.