i was surfing the web till i found an article saying that apple has quietly added a restrictive copyright protection mechanism to its new MacBooks that is preventing customers from watching movies on external displays.
This has been secretly included as copy protection scheme called High-bandwidth Digital Content Protection (HDCP) in the external display ports on the latest models of those MacBooks, released in the middle of October.
Apple has not disclosed the new anti-copying mechanism, and now increasing numbers of customers are discovering that they cannot play movies bought from the iTunes online store on many external monitors, TVs or projectors.

i guess that many of u guys who use MacBooks already knew about this , was just mentioning to get ur opinions about this ...