Yes there is. You probably have the install on a fat32 file system. Bad idea. Set up a ext2 file system on the usb stick and install on that. Then your standard Linux file permissions will protect the system the way it was designed to.
Insanity: Doing the same thing over and over and each time expecting a different result.
Democracy is 2 wolves and a lamb voting on the menu. Liberty is an armed lamb protesting the electoral outcome. A Republic negates the need for an armed protest.