Microsoft says that they will soon send email to users when Office 365 detects a higher than normal number of file deletions in SharePoint Online sites and OneDrive for Business accounts. There’s no real detail provided as to what counts as a high volume or why Microsoft is sending the notifications.
The security company Avanan says that 10% of Office 365 users are affected by “PhishPoint.” That estimate seems pretty high to me.
SharePoint Online and OneDrive for Business sites will soon boast 100 minimum versions, which they need to power features like AutoSave and OneDrive Restore. But if you work for an organization that doesn’t want to use so many versions for files, you can update your SharePoint tenant configuration to disable minimum versioning. That is, provided you do so by September 30, 2018.