My brother retrieved his hard drive and noticed that the hard drive has been modified. Many files have been copied, deleted, access, etc. He had asked this person if they have accessed the hard drive, and modified it, and they have admitted to copying. He had mentioned files missing, and that is when the person admitted to deleting and modifying files. This person did not have permission to access the hard drive. Is there any way that the person can be sued or is it illegal for that person to access and modify his hard drive without permission?