The Dell Latitude business laptops now have a wired led and wired switch. Besides the white led, there’s no indication which is on or off, and I don’t trust any of the software or firmware chain to be reliable. (score one for macs being transparent and prescient)

Dell should go back to the basic design of the Latitude E6400, but with modern electronics and screen of course, and drop the optical drive. The keyboard on that laptop was fantastic, and the single captive screw on the back panel was great for serviceability.

For some inexplicable reason Dell has chosen to mark the button as "mute mic" (mic icon + X). So if the LED on the keyboard is lit up, the microphone is off, or rather, the microphone muting is on on. Brilliant design.

Yeah, the physical barrier is key. It's not that hard, and provides absolute certainty. As indicated by this thread, software experts (rightly) don't trust software by itself enough. It's by the same rationale software people are proponents of electronic voting machines printing physical, verifiable paper copies of votes.

My Latitude 7440 has a physical slider switch that covers the camera, in addition to turning it off in a software-detectable way (it shows "no signal" and not just a black screen once the slider is about 50% covering the lens). My only criticism of this is that it's subtle and at a glance hard to tell the difference between open and closed, but I guess you just get used to the slider being to the right.

I was just testing and the white LED comes on when I open something that wants to use the camera, even when the cover is closed. This seems like a useful way to detect something (eg malware) trying to use the camera, and is a good reason to not bluntly cut power to the entire camera module.