When buying a webcam, make sure it has a light that turns on whenever the camera is on, and which cannot be turned off in software.
"Why," you ask, "would I need this?"
For an answer, read this article, titled "Google researchers use ambient audio to augment the television experience."
Head spinning yet? 10ms today, how long tomorrow? Audio today, video soon? Google today, who next?
And when other companies follow the lead of this stellar "do no evil" leader, to what extent will they do so? Perhaps, the next generation of Yahoo and Google toolbars, or even Microsoft Windows, will have this spying feature integrated into them?