What I like best about Predator ($29, 30-day free trial) is the concept: Instead of using a password to unlock your computer, just insert your thumb drive and your computer instantly unlocks. It may not be as magical as BioTrust, which lets you unlock your computer using a webcam and your face, but it's still a nice idea.Sadly, the idea is one of the few nice things about Predator. The execution feels clunky and insecure in several ways. First, it works by polling your USB drive at timed intervals (every 30 seconds, by default). That means that once you pull the drive out, your computer may take up to 30 seconds to lock, while you sit there and wait (best case scenario) or just walk away assuming it would lock.Predator uses its own mechanism to lock your computer. When locked, you will not see the familiar Windows unlock screen, but a black screen built into Predator. Once you plug the thumb drive back in, your computer will unlock. Thankfully, unlocking is nearly instantaneous--you won't have to wait 30 seconds. Once the computer is unlocked, you can use Predator to see if anyone tried to unlock your computer while you were away.You can also unlock your computer using a password. This is not the same as your Windows login password--it's a password specific to Predator, which you have to set within the application. When the computer is locked by Predator, you can tap any key on the keyboard to pop up an unlock prompt. You then have 20 seconds to enter your password. If you fail to enter the correct password, Predator can sound an alarm through the computer's speakers.When you unlock the computer using a password, Predator does not resume monitoring the USB ports. You have to manually reactivate monitoring every time you unlock your computer using a password instead of a thumb drive. This means you could unlock your computer with a password, plug the thumb drive in sometime later (expecting to use it as a key at the end of the day) and then plug it back out, and nothing would happen. Your computer would not lock, not even after a minute. You might be gone by then, thinking your computer is just slow to lock.Predator is a nice gimmick, but it doesn't use Windows events to detect when your thumb drive is pulled out, doesn't resume monitoring automatically, and bypasses Windows' own lock screen. If you're serious about security, you would be better off sticking with the native Windows offering.