It ain't just SM, facebook or any other - it's the internet - that computer, cell phone, whatever that you are hooked into. Met a family the other day - man and his wife and 4 children - no cell phone, no electronic toy, go outside and play, let's go fishing, or get your bikes and let's go for a ride. It's even FAA/Pixels - time just flies by and we are so absorbed we forget those things which need doing, which we intend or intended to do - and then it's bed time - there perhaps you fold up your legs and have your tablet or lap top right in bed with you - worse than having a cat or dog. The only way you could set time limits is to have a mechanism in the machine you are hooked to that would simply shut you down - no matter what you were doing after a specified time.