And yet, as this example shows, thanks to copy protection systems it usually does:
on his classroom's projector with a new aluminum MacBook over lunch, he
was denied by the error you see above [an HDCP error]. John's using a Mini
DisplayPort-to-VGA adapter, plugged into a Sanyo projector that is part
of his room's Promethean system. Strangely, only some iTunes Store
movies appear to be HDCP-aware, as other purchased media like Stargate: Continuum and Heroes season 2 play through the projector just fine. Attempts to play Hellboy 2
or other HDCPed films through the projector via QuickTime also get
denied. Other movies that don't work include newer films like Iron Man, Star Wars: Clone Wars, and Love Guru, but older films like Shawshank Redemption are restricted as well."
Studios and other content companies should start to realise that this kind of stuff only discourages legitimate customers from paying for their products, and encourages them to pirate it.