The LED light on the webcam is bypass-able. On many cheap laptops it is controlled in software (at the kernel level), but even on Macs where it is meant to be hardware enforced it can be bypassed:
Disabling the camera LED is a fairly standard feature in malware suites. Even a lot of USB webcams control the LED from software. The LED is just a feel-good feature.
This isn't quite accurate. It can't be easily disabled on most laptops. The way to disable it on Macs is extremely sophisticated, and no malware currently does that, except maybe NSA malware.
You still shouldn't really trust it, but the situation is not how you're making it sound.
my laptop (Asus EEE 1215B) happens to have a physical slider that goes in front of the webcam (it also happens to be a bit loose and the tendency to slide to the "open" position if I pack it in my bags .. hmmmm ...).
The only surefire way to disable your webcam is to place a little square of gaffer or electrical tape over it. Total cost: $0.01 and can be reversed in an instant.
I started doing this after seeing a guy selling widgets for it on Shark Tank. Though, I followed the shark's advice and just used a post it. But as someone whose laptop is pointed at their bed, this seemed like a necessity.
I assume you can disable the microphone with a microphone compatible headphone jack plugged in (and cut the cable off). Though it disables your speakers too.
http://www.washingtonpost.com/blogs/the-switch/wp/2013/12/18...
Disabling the camera LED is a fairly standard feature in malware suites. Even a lot of USB webcams control the LED from software. The LED is just a feel-good feature.