As a parent with custody, you have the right to discipline your kids. If this means removal of electronic privileges (e.g. no TV and no phones), so be it.
So court wise, no hard and fast rules, just be reasonable. The court doesn't like to see one parent stopping their children from having access to the other parent (in normal circumstances - e.g. no violence, drugs, alcohol etc)
re: Their father, unfortunately, it is hard stopping unreasonable from being unreasonable.