Its called respecting copyright crewmeal.
Not suggesting you don't since I don't know what you watch. But I do know that much of the content on Sky, the BBC and other transmission mediums are covered by copyright laws and content licenses.
I know but there is so much crap on these channels at the moment, that's why I use iplayer 4od etc. All I do is stream via my Macbook to my Samsung smart tv. Since there are so many YouTube files that are more than an hour long, it's a great way to watch them. YouTube have to decide if they break any copyright laws.