I mean... being proactive should have been learned from Snowden's reveal about BIG brother moons ago one would think. Clearly, some folks are just a pillar of salt.
This is why I keep all my files and emails on my local server. I keep it backed up and I control who has access to it and in a pinch I can remove it from any internet access. When you hand your files to a third party, you're at their mercy - if they change policies, screw up or go under, you're screwed and often have absolutely no recourse or way to recover your files.
Losing or being unable to access important data is certainly frustrating, but it's even more frustrating when it happens intentionally. This recently happened to a user who uploaded his most important files and photos to Microsoft OneDrive, and was subsequently locked out.