[gottam]

It's because they DO look through people's files for their own purposes. Example:

https://blog.onedrive.com/onedrive_changes/

> a small number of users backed up numerous PCs and stored entire movie collections and DVR recordings.

I'm pretty certain they didn't get permission to look at their users movie collections or DVR recordings, they were just flagged for high usage and they went right in to see what those users were storing. For any form of data collection they do, it's a guarantee they're analyzing the outliers... in fact they're practically bragging about the fact they do.