It turns out that full disk encryption really does what it says on the tin -- encrypts your data so that people without the passcode can't get at it; even the security agencies.
A recent research paper has revealed that modern full disk encryption has got to the point where it's just not possible to decipher the data without the password. The Feds are worried that it's going to compromise their investigations into everything from fraud to terrorism, as they simply can't read disks that are properly secured. Hardware-level encryption often has some sort of self-destruct mechanism built-in against tampering, where as software-level encryption requires the kind of advanced data dump cryo-techniques that are pretty tricky in the field; and how do you get a powered-up desktop back-to-the-lab for data forensics without turning it off?
It may be an issue for the rozzers, but I have to say I'm quite pleased in knowing that if I really wanted to, I could keep prying eyes out of my data for good. [Digital Investigation via ExtremeTech]