Ghost is one of the best blogging platforms, in my opinion. It's open source, so you can personally audit the code, if you wish. More importantly, it's easy to host on your own server, so you can store your data yourself.
The Ghost team has finally released Ghost 1.0! Congratulations to the team and community!
You may notice that I haven't migrated yet. :o) I'm excited to upgrade as soon as I have the time! <3