Q: Can CloudSOC Gatelets block uploads/downloads if the Sync client is being used?
A: Yes, CloudSOC Gatelets can address the common activities like file upload/download when using the Sync client.
Q: Can CloudSOC Gatelets manage file edits? For example, a user syncs a file to OneDrive that doesn't violate a DLP policy. However, at a later time they edit the document on their machine and add data which violates a policy.
A: File editing (even without the sync client i.e. when you take a file on OneDrive and say open with MS Word) results in the creation of incremental file chunks that are sent from the client to OneDrive. This means that the full context of the document is only available on a full download or at rest using the Office365 Securlet. As such this would require a combination of Securlet and Gatelets to capture a comprehensive DLP strategy.