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My privacy feels invaded by the "active" light on my webcam turning on when I boot Ubuntu, and again when I login. It stays on for 3-4 seconds, then turns back off.

It's a Creative HD 1080p webcam that sits on top of the monitor, plugged in via USB.

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    Why don't you just unplug your webcam when it is not in use if you are worried that somebody is using it to spy on you? Or put some tape over the lens or something?
    – user364819
    Feb 22, 2015 at 19:00
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    The thing really to be more worried about is if someone is spying on you using your built-in microphone (if you have one) because it does not have a little green light to tell you when it is on, thus you will never know if you are being listened to or not.
    – user364819
    Feb 22, 2015 at 19:07
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    How can you be sure that the light on the webcam indicates that it is sending the video stream somewhere? In my experience, it might just mean that the webcam is being initialized. You should check with the tech specs of the camera to see what the light may or may not indicate before assuming the worst case. Feb 22, 2015 at 21:43
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    @Rinzwind the attacker would need access to the machine to do that, and if he has access then he can very well bring his own ffmpeg binary along. Anyway I proved my point, and I'm just saying that if my webcam ever lights up like that I'd suspect a compromise and won't be satisfied until I find the process that's activating the cam. Saying "it's normal" without any proof is too big of a risk. By proof I mean whether that cam has the same behavior on other machines. I'm not going to waste my time arguing, bye and have a nice day.
    – user249743
    Feb 23, 2015 at 10:08
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    Thank you @AndréDaniel "Saying "it's normal" without any proof is too big of a risk." - The bottom line is, a motivated attacker certainly could manipulate the machine to photograph-and-transmit an image of the person sitting down to use it. Why anyone would launch such an attack is pure speculation, but the matter of importance to me is: How might a user investigate for themselves whether their machine was behaving maliciously, using the tools available in their Ubuntu installation? Feb 23, 2015 at 15:35

3 Answers 3

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What is watching me?

Nobody. Without any proof (I did google for it a little bit): I seriously doubt that a webcam can transmit a stream to the outside world before the desktop is active. It would be very complicated to make software to do that and it would require you to install it yourself.

And why does this happen?

It is the device being detected by the system. First when the USB system is started the camera gets powered up it will tell you by flashing the light. And the second time will be due to the program that is started during boot to use that webcam (that will probably be the program "cheese" or "skype") that checks if it can find a camera. That again triggers the light to flash.

If you want to get rid of the second one: disable the program to start at boot time and start it manually when you want to use the webcam. If it is indeed during login check "dash", "startup applications" and check for programs that can use webcams; if there is one you could disable it there.

If you want to get rid of the first one you probably need to unplug it before booting (that will also get rid of the second time). As soon as you plug it in it will flash when the webcam gets detected by the system.


Some independent topics related to this (and not per se Linux):

Use common sense. if it always flashes during boot and always at those two specific moments with every boot I would expect this to be normal behaviour of that webcam.

When you need to worry about it flashing is when it flashes during normal operation; When you are using your computer and not using the webcam. If it flashes then you should investigate this.

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    @Shutupsquare it could be worse; I once had one from MS that did not stop blinking -ever-.
    – Rinzwind
    Feb 22, 2015 at 19:55
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    I LIKE that it blinks when probed. Say you had some super-advanced thing that skipped the whole v4l2 layer and just tried to grab the webcam memory directly. I'ld like it to blink... I wouldn't run about whining about it. Feb 22, 2015 at 19:56
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    @hbdgaf How could you tell if someone is watching you, or your OS is just probing what's on the other end of the USB bus?
    – squareborg
    Feb 22, 2015 at 20:10
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    This answer is wrong. I've never seen a webcam light up during initialization (the LED is hard-wired to the sensor's power, so it lights up only when the sensor is powered and captures video, it has nothing to do with the camera's microcontroller initializing). If the LED lights up it means a process is accessing it, whether it's malicious or not we don't know yet.
    – user249743
    Feb 23, 2015 at 4:54
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    @AndréDaniel "I've never seen a webcam light up" I have. Nath has. Several ppl in Ubuntu Chat have. I provided 2 links that state it happens. Your just have not seen enough webcams.
    – Rinzwind
    Feb 23, 2015 at 8:06
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I can confirm this happens on a clean install of Ubuntu and MINT. It doesn't matter which desktop you are using. Don't worry about it.

P.s I have a logitech webcam too. Nothing to do with branding here.

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  • Thanks for confirming that the behavior occurs with a clean install. Feb 23, 2015 at 15:40
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Take a look in /dev/ folder, you will find a file which is /dev/video0. This is your webcam. In order to appear there, in the list of all devices, udev will need to initialize it somehow. That's why it blinks.. Then it's basically just hanging around there in the wait state until cheese or some other program needs to access it, which is when the light will become constantly on.

Same occurs every time I plug mine in - it blinks once. Why does it do on start up and shutdown ? Because the script for the service udev (which is in /etc/init.d/udev, by the way) runs on shutdown and startup, to bring devices up and down.

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  • What about my weird camera where the light remains on until the first usage, and only when that first usage actually finishes it turns off? How can I work around that, besides blacklisting uvcvideo? Oct 7, 2018 at 10:33
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    @PaulStelian Well, you could "simulate" first usage - there's way to script taking a snapshot with webcam, so you could have a script that waits for webcam to appear in device list, take snapshot, and dispose of it. But that's just a workaround. I'd recommend asking a proper question on the site and maybe someone can help troubleshooting it. Oct 7, 2018 at 10:43

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