This link is in French but as a summary: technical report shows that M365 Word and PPT contents leak to US servers (augloop.office.com) as soon as you open a document on a local installation of Powerpoint or Word, unbeknownst to users.
This is potentially huge!
This is different : no sync to other Cloud services enabled. This is not disaster recovery or backup, file contents are sent thru json. You use your Word / PPT application locally, and without your knowledge file contents are sent to US servers at the augloop.office.com endpoint. This is a clear privacy and confidentiality risk. It is bundled with the “connected experience” services, and the only way to deactivate it today is thru a registry key in Windows. And it’s the default behaviour, the user is not informed. This breaches several GDPR principles, not to speak about MS spying on your confidential contents when using a local install of their software on your PC.