I try in vain to restrict access to the image directories to prevent users from deleting images or folders.
I followed the tutorials but nothing to do, it doesn't work. My question is how do you assign a jce profile to users?
Have you created a separate profile for the users?
If you have, and this profile is assigned to a particular user group in Editor Profiles -> Setup, then make sure the ordering of the profile is set to be above the "Default" profile, ie: set the Ordering of the new profile to 0 Order First
Just because you're not paranoid doesn't mean everybody isn't out to get you.