I am using cognos 8.4. and i am cognos Admin. Some folks are changing the capabilites ex: removing groups , and disabling the public folder. how to find out who is doing this kind of activities. I dont have idea about SDK.other than that please provide a way.
Change the permissions for 'Public Folder' by denying access to write or change policy to the groups you want.
Change your login to mimic the users and test security to find out what changes gives you the correct security.
It sounds like you're looking for an audit trail of user activity. AFAIK, Cognos does not provide this level of detail, even at the most fine grained level of logging.