Wait so are you saying that the google encryption isn't secure? And how do I know dm-crypt / luks go the way of truecrypt?
Autists / schizos are in on the fun too.
Seriously though if you have a solid state drive or flash drive it literally cannot be (securely/totally) securely erased except by the built in tools. The only way is by encrypting the drive from the start. That means passwords, cc info, etc.