Sounds like the age to me. And I don't think taking things away from them is a bad way to parent, they have to learn that their actions come with consequences, and there isn't much that means much to them these days.. LOL

I don't usually take tv away or anything, or use that as a reward though - I'm more of a "reward with a cuddle" or nice drink or something like that - and punish with being sent to the corner. Usually just the threat of being sent to the corner is enough to stop the bad behaviour.

DD1 is very rough at the moment though, and very disobedient - so its definitely the age