Logitech makes a lot of webcams.
Logitech LED Disable - Printable Version
How to Secure Your Webcam
How can you be sure that no one is watching you without your permission?
Many webcams on notebook computers have indicator lights on them that let you know when your camera is actively capturing video. It may be possible (on some cameras) to disable the activity light through software hacks or modifying configuration settings. So, just because you don't see an activity light on doesn't mean that your webcam isn't still capturing video.
Webcams | Hacking | PCs | Laptops
Although many web cameras offer a telltale LED light which indicates whether it is active, Fairfax found many security experts didn't trust that it would operate correctly if a hacker compromised their machine. After all, hackers have found ways to disable some webcam lights.
Linux Ubuntu Disable WebCam LED Light | SpaceTech
http://www.clemson.edu/ces/crb/ece49...cam_manual.pdf [page 10]
Remove the check from the LED On check box to turn off the status LED on the front of your webcam.
Guard Yourself with these Tips on Webcam Safety
Look for the camera's operation light coming on when you're not using it; this is by no means a failsafe -- recent research suggests hackers using special web camera programs may be able to switch off the light.
I wouldn't count on the light being a sure indicator.