There is an exploit of the Mac iSight cams published by researchers at Johns Hopkins U. Check this:
http://appleinsider.com/articles/13/12/ ... ting-users
Some things to keep in mind.
1. It only affects 2008- and earlier Macs (iMac and MacBooks) and older versions of OS X (prior to Mountain Lion). My little MacBook is a 2008, but will run Mavericks and Gatekeeper, so this exploit won't work on it.
2. It is a firmware attack. In any version of OS X that can run Gatekeeper (Mountain Lion and later), it will not work
3. The exploit will not work on the newer Macs.
4. If you are in the least concerned about getting your cam turned on without you knowing, a piece of duct tape will resolve the issue.
Duct tape. Like the force, it has a dark side and a light side, and it holds the universe together.
It took these eggheads at Johns Hopkins years to figure this exploit out, and a small square of duct tape will mitigate it. Make one wonder who paid for all that research time.