You should never leave your laptop unattended in a public space. If you need to leave your workspace, take your laptop with you or ask someone that you trust to watch it while you’re away.
In your residence hall, it's a good idea to use a laptop cable and lock to physically secure it to a piece of furniture. To secure your data, set a screen saver that requires a password.
Many laptops also offer hard drive encryption for added data security. For added peace of mind, some students have purchased and installed LoJack for Laptops, which can allow police to locate computers that have been reported stolen.