Some hackers do it because they can, others have more malicious intent. The bottom line is if you're not careful, what you do in the privacy of your own home may not be as private as you think.
It's known as a RAT, or a remote administration tool.
"It's a generic term for someone being able to own your computer and control it from a distance," said Kurt Opsahl, a senior attorney from the Electronic Frontier Foundation.
Ratters can use the RAT to gain control of your camera and record your every move. Ratters can startle you. They can just stare at you. Ratters can even spy on you in your bedroom.
"I'm aware of one instance in which a user, a female user, was using a laptop in bed and a compromising picture was taken," said Doug Tygar from UC Berkeley's computer science department.
The UC Berkeley student who declined to be interviewed had to call police after the ratter tried to blackmail her with the picture.
"We're seeing it happen increasingly often, especially since virtually all contemporary laptops now come with built in cameras and microphones," said Tygar.
In 2010, a school district near Philadelphia was sued after it was discovered it used cameras on school-issued computers to monitor its students. The district went so far as to accuse a student of selling drugs.
"Even if it's just a photograph of you sitting in front of your computer, that is intruding into a private space. A space that has a reasonable expectation of privacy," said Opsahl.
These attacks on individual privacy come from the same family of attacks used to target institutions and even governments. Virtually every major bank has been hacked at one time or other. Both Iran and China have been accused of being involved in cyber security attacks on such major banks as Bank of America, Citigroup, Wells Fargo and US Bancorp. Irfan Saif of Deloitte & Touche has helped clients monitor their own security.
"Obviously the concern is that people are eavesdropping, keeping an eye on people or listening into conversations they shouldn't and they perhaps have visibility into spaces they should not," said Saif.
Tygar says such high-security government installations as Fort Meade in Maryland won't allow employees and visitors to even bring in standard lap tops or cellphones.
For individuals, the solution is simple. Cover your camera with a piece of paper or tape. But Tygar from UC Berkeley suggests shutting down your microphone as well by hitting the F1 key during the boot sequence.
"That will bring up a basic part of the computer and you can turn off the microphone and the camera from there," said Tygar.
In fact Saif thinks concerns about the microphone should be just as high as concerns over your camera.
"There's a good likelihood too that they're not only observing what's going on in the room. They are also listening to what's going on in the room," said Saif.
All three people we talked to encourage everyone to keep their software up to date, install the latest patches, and be cautious about opening attachments and suspicious links. If you don't, this could happen to you.
We discovered it's not difficult to find instructions on how to hack into someone's camera. So this is something we all should be aware of and take the appropriate precautions.
Here are instructions on disabling built-in cameras:
http://www.ehow.com/how_5799246_disable-isight-camera.html See also: http://techslaves.org/isight-disabler/
For Windows: http://peripherals.about.com/od/webcamerasvideoinputs/ss/DisableaWebcam.htm
For most laptops, it is also possible to disable the camera in the BIOS. The settings vary slightly from manufacturer to manufacturer, but they are typically found under either "Security," "Peripherals," or "Advanced."
Here are instructions for entering the BIOS: http://www.pcworld.com/article/241032/how_to_enter_your_pcs_bios.html