Is there a way to lock a folder's icon without making its contents Read Only? I have a network share that is used by a large group of kids. They love changing the icon of this folder, which causes a lot of debate. I know that there is a hidden file that specifies the icon; can I lock this file so the icon of the folder can't be changed anymore?
You're exactly right. Here's how to lock the file that controls the icon:

Show hidden files.
Navigate to your folder.
There will be a file called Icon inside it.
Go to the Get Info window for that file and check the Locked checkbox.
Try to change the icon. You can't. Ta-da.