Apparently quite a few webcam models can be activated without also activating the light that indicates the webcam is in operation. (This trick is mostly used by hackers and the FBI).
Can anybody provide some insights into why the linkage of the two is handled by software? Is activating the camera without turning on the light an intention feature, or just an unfortunate side-effect of cutting costs and/or the trend of moving as much stuff as possible into software (including firmware)?
I suspect it may be intentional, so that the camera can be used as a light sensor (to adjust your displays brightness to match the surroundings), but I’d really like some confirmation or disproof from a source more reliable than my own logic.
I would imagine that there might be some way to use the camera as a light meter for autoadjusting light levels on the screen? Actually I have a Pavilion dv7 and it does not have any lights associated with the camera at all. I don’t worry about it, but I also will admit that I have a small strip of tape across the lens. I don’t worry about myself, but I have underage goddaughters and I don’t want one of them possibly caught on camera at all.
There’s no “ON” switch on the camera. The camera is always ready to output a data stream, and it’s only in software that the decision is made whether to use that data or not - so there is no way to tell the light to turn on, except by software command. Even if the camera can be powered down, that would mean that the light would be on all the time the camera had power, whether the computer was recording or not.
Depends upon what you mean by “activate”. It typically does not mean “apply power to”. In general webcams are USB devices, and are always powered. Internally there will be a a sensor and circuitry to provide UVC (USB Video Device) capability - including a USB bus interface.
Making a Webcam operate is not a trivial task - the range of different UVC devices is huge, and the interface standard provides a set of protocols which are used to negotiate with the device about its capabilities and how the user program wants to use those capabilities. The computer will need to negotiate things like resolution, frame rate, data rate - including transfer protocol type, and may include negotiation of colour correction, focus control iris control, access to still image capture, and finally the camera may be commanded to start streaming data. This is usual for USB devices - the onus is on the driver code in the computer to command the device to set itself up and operate in a very fine grained manner. The webcam interface code in any operating system is required to support these protocols, and they do. Somewhere in the deep recesses of the control protocol may be a command to turn on the indicator light on the camera. (I couldn’t find it in a cursory check - it is quite possible it is implemented as a separate USB end point, and is not even part of the UVC definition.) The point is that along with every other aspect of operating a UVC device, turning on the indicator light is a separate command to the the device. The onus is on the controlling code to do this.
In general the indicator light is a polite warning, it isn’t and has never been intended to be a privacy or security measure.
So the answer is a mix of your suppositions. Webcams have never been designed to be a stand alone - turn on and it does everything internally - device. This is the nature of USB devices (and does have some relationship to the ability to make cheap devices where the real work was done in the host - printers and scanners are good examples of how this works). Perhaps the desire to allow webcams to encompass a wide range of capabilities and thus provide a complex and wide ranging set of operating options has something to do with it as well. But modern devices are not simple dumb things, and are much more like extensions of the inside of the computer. It wasn’t that long ago that you would implement a webcam capability with a video capture card inside the machine. In many ways the modern webcam is the same device, except that the capture card has migrated to be inside the camera. The wide range and complexity of control options remains.
Webcams aren’t necessarily USB devices: A lot of laptops nowadays have them built in. And I can confirm that mine does use it to adjust the brightness of the screen: If I stick my thumb over it, my screen gets dimmer.
Typically however they are still USB devices, just on an internal USB bus. A large amount of the additional functionality in a laptop comes this way. It makes things easy for all parties.
We will probably custom build when mrAru retires, being handicapped it is easier to do so than convert in most instances - we already plan on installing hidden cameras in a system to observe outside so I can check live feed if I hear an odd noise, and get evidence if we get broken into. I figure that we will also have a few general inside cameras as well for when we are away from home.
I have been burglered twice, and had a creepy landlord and it really is a nasty feeling to realize that someone has been in your place poking around when you aren’t there. I had a friend who came out of her shower to find her landlord in her bedroom with no prior notice.