If it's connected to the Internet, it seems at least a little vulnerable.
But surely we can trust that workhorse selfie-generator, the iSight webcam built into the top bezel of Mac laptops. Or... Maybe not. Yesterday, security researchers Steve Glass and Christopher Soghoian were passing around a National Security Administration factsheet with a little bit of advice for Mac users on how to "harden" their computers to attacks.
Among the tips, we find the following suggestion: "Disable Integrated iSight and Sound Input."
"The best way to disable an integrated iSight camera is to have an Apple-certified technician remove it," the NSA writes (emphasis added). Then, you might try "placing opaque tape over the camera" or try the software-only method of removing one of the components of Quicktime's files. And if the NSA doesn't trust a particular piece of hardware can't be used for surveillance, it's probably safe to assume an average user shouldn't either.
The built-in microphone comes under scrutiny, too. The NSA suggests setting the mic input level to zero and removing a file that cripples the sound system.
The rest of the tips are available in this handy, seemingly laminateable PDF. They include firewalling instructions, file deletion suggestions, and several other procedures. In fact, the NSA maintains an archive of factsheets on protecting its employees, contractors, and associates, but you can use it to protect yourself from hackers -- inside or outside the government.