Apple now has a restrictive copyright protection mechanism on its new Macbooks that prevents its users from watching movies on external displays.

It has surreptitiously included a copy protection scheme called High-bandwidth Digital Content Protection (HDCP) in their external display ports which are in the latest MacBook models that came out in October 2008.

Apple never acknowledged this new anti-copying mechanism as many new customers have discovered they can't play movies purchased from the iTunes online stores on external monitors, TVs or projectors.

HDCP, which was released by Intel in 2001, is designed to  prevent digital pirates from outputting movies to copying devices, like digital video recorders.

This also prevents movies from playing on older computer monitors or flat screen TVs.

As use of Apple laptops and iTunes online stores have become universal, this issue is a serious one.

Customers are complaining that they weren't aware their viewing devices weren't compliant with the HDCP standard, which has forced them to watch their movies purchased from the iTunes Store in other formats.

It's a sensitive issue for studios as iTunes purchasing model involves downloading content straight to a hard drive, where it's defenseless to copying.  Thus they're easily copied and shared with others.  Whereas movies from Vudu and Netflix are more difficult to copy and easier to police.

Source