I can legally watch my television. It picks up broadcast signals from the air. I don't pay for it. If a friend came over, we could watch it together.
I can use my VCR to record a show on television.
I could let my wife watch the show I recorded too. And if a friend came over to visit, and we could all enjoy the show together on our own schedule.
But my friend is busy. I lend him the tape. He watches the program at home later. He brings back the tape.
We both like the program and decide we want to watch the next episode also. We both record the program. We watch on our own schedule.
One week, I forget to record the program. I borrow my friends recording and make a copy. Is this substantially different from both of us recording it off the airwaves ourselves?
Is it okay to use peer to peer filesharing protocols to share television programs? The answer seems murky, but why?