Flash has a security issue where a hacker can take control of your microphone and/or webcam just by your click on a link. The issue affects Flash across all platforms and it won't be fixed until the next version of Flash, Flash 10.

To protect yourself in the meantime, you need to edit your Flash settings to deny Flash access to your webcam and microphone. The link below gives the long explanation on how to do this. The short explanation is find a Flash video on a web page. Right-click on the Flash and select "Settings". You'll see various tabs with icons that almost no sense. Click on the various tabs until you find the panel that has an option regarding access to your microphone and webcam. Choose the "always deny" option and you'll be protected.