Prevent use of item level permissions?

[Jakob Rohde]

Hi

Is it possible somehow to prevent users of SharePoint Online sites from using item level permissions/breaking inheritance - even for site owners?

/Jakob

[#2]

No, its not. If the user has permissions to change security at the item / document level there is not a way to block this behavior

[#3]

While you cannot block it, you can Audit many of those types of events. See https://support.office.com/en-us/article/Search-the-audit-log-in-the-Office-365-Security-Compliance-... for the instuctions.

Some of the relevant auditable events include , 

Broke permission level inheritance	PermissionLevelsInheritanceBroken	An item was changed so that it no longer inherits permission levels from its parent.
Broke sharing inheritance	SharingInheritanceBroken	An item was changed so that it no longer inherits sharing permissions from its parent.