I don't think that it is right to say that it is a waste of time to use these Social Media services. If it is so it would be also a waste of time to hang around with friends or walk in the park. That's not true. People want to have fun and you can have fun on FaceBook. You can also have fun with friends and so on.

What I'm trying to say is if you want see such things as a "waste of time" then shouldn't go out with friends or to the cinema instead you should work or learn something.

Everyone should be free to choose what is a waste of time for himself.

(sorry for my bad (!!) english. I hope you got the idea) EDIT: fixed some grammar errors (I bet there are tons of left)