Last year a friend couple uploaded photos of their one-year son (I understand it were those "bathtub photos" parents like taking to embarrass the children when they grow up) just to get their paid account blocked. They panicked because they used Skydrive to "securely" store lot of pictures, including their travels, honeymoon, etc. The husband was a bit tech-savvy, but I failed to convince him to always PGP-encrypt the files and rename them to non-significative names before uploading. At least, I made them never trust these services again.

I, personally, never use these file storage services to hold anything but encrypted data assuming that such data can disappear overnight without any warning.