For one thing, in two of its three modes of operation BitLocker requires a cryptographic hardware chip called a Trusted Platform Module and a compatible BIOS. These chips are yet to become widely available much less deployed. The third mode requires a user to insert a USB device that contains a startup key in order to boot the protected OS.
I don’t think anyone would find it much of a surprise to know that BitLocker won’t protect you from the Government or those who understand what they need to get at your data. Either way, this is still likely a decent technology to protect your data from your loved ones or friends. But… is that even worth the price of admission?
Source: The Register