Linux: Forgot your password? Let's reset it!
How to bypass or reset the root password of any Linux distribution with Grub 2... all you need is physical access to the machine, reboot it, and change a couple of boot parameters from the Grub menu. TA-DAAN! From there, you can do ANYTHING, from changing or resetting any user's password to wiping the entire hard drive, if you're a malicious person.
Although this is an old trick, password-protecting GRUB remains a niche practice.