I recently dug into this because I accidentally trashed my wife’s OS which was encrypted with bitlocker. PITA btw and I couldn’t beat the encryption
Bitlocker encryption key hash is stored in 2 possible places. First is an unencrypted segment of the encrypted drive. This is bad because it’s pretty easy to read that hash and then decrypt the drive. The second place is on a Trusted Platform Module (TPM) which is a chip on the motherboard. This is better because it’s much more difficult to hack. It can be done but requires soldering on extra hardware to sniff the hash while the machine boots up. Might even be destructive… I’m not sure.
Either way a motivated attacker can decrypt the drive if they have physical access. For my personal machines, I wouldn’t care about this level of scrutiny at all.
Anyways you can see if any open source solutions support TPM.
An interesting discussion! You’re probably right about most Lemmy instances. But it’s entirely possible that some instances are running a modified version of Lemmy that collects more data. And only those admins will understand why. They could sell it as easily as any company.
You need to trust your service providers or accept what they’re doing.