Well, here's just one example I can give you (despite it not being a very good example):
I once had to sit and watch HANNAH MONTANA with my niece one time... the acting was absolutely terrible. Miley Cyrus's performance, all around, was very hammy and kind overly exaggerated, like she knew there were cameras there, and knew she was being filmed, and being watched... that's one complaint I have with a lot of these live-action kidcoms on Disney, Nick, what have you, is that the stars really don't know anything about subtly or just flat out acting natural, they always have this, "LOOK at ME! I'm on TV!" vibe in their acting, it's just not believable, it's really difficult to sit through and watch these youngens trying to outdo their own selves.
I mean I can't speak for everyone else, but that's just my own little beef.