On one of my emacs it sometimes tells me I don't have permission to replace an item in the applications folder and doesn't even ask for authentication. I went to change all the permissions in the applications folder so that the owner was the system (some of the items have an unknown owner) and admin could read and write. But when I clicked apply to all items in folder it wouldn't let me as it said I didn't have permission even though I used an admin account. Rather than search through all the 124 items in the applcation folder one by one I was wondering if I can use terminal to force all the permissions to change. Also is it OK to make the owner of self installed apps, the 'System'?