I'm using a normal MacBook, running the latest version of Snow Leopard. A few minutes ago, I was online, and my internet (Verizon Mobile Broadband) was acting up. I disconnected it, but the application (VZAccess Manager) was taking too long to disconnect, so I just pulled out the USB 3G adapter. Right then, my screen dimmed from top to bottom over about a two seconds and a warning popped up in the middle of the screen. It was gray, with a lighter gray power symbol and had instructions in several languages stating something along these lines: "The computer needs to be shut down. Press and hold the power button, then press the power button again to turn the computer back on." Those aren't the exact words, but that was the general idea. When this appeared, I was unable to do anything. The trackpad wouldn't respond, the keyboard wouldn't do anything, etc. I turned the computer off by holding the power button (my only option), and then turned the MacBook back on. As soon as I did, the webcam also turned on, and remained on. Once it reached the log in screen, and the webcam was still on, I force-shut down the MacBook again. Upon starting it up again, the webcam didn't turn on. This is quite unnerving to me. I don't like the idea that the webcam is watching me without being in my control. What could cause this? I know it's a Mac, but could this be some kind of Mac-specific virus? Or, is it simply some kind of system error that isn't anything to worry about?