DS (8) is currently in his room wailing and shouting that he wants different parents because we're so cruel and don't care about him and everything is not fair.
The reason is because apparently everyone else at school has a tablet or phone of their own that they can use whenever they want. We have a tablet and a laptop that belong to the whole family rather than just being his, but he's the only one who uses the tablet so it's virtually his anyway. DD occasionally uses it but not much. The laptop has minecraft on it and during the day, if we don't need to work on it, he's allowed to use it.
We set time limits, not exact times, but maybe something like 'you can play on it until tea time and then put it away until tomorrow'. So he'll have an hour or so on it most days, sometimes more and sometimes less.
But apparently everyone else can spend as long as they like playing computer games and can sit in their room all day with it if they like. 
So AIBU in not letting him use it more or not letting him have one of his own? From the wailing going on at the minute I'm starting to feel as though we're the worst parents in the world.