Re: [Strint-attendees] [perpass] GHCQ Webcam Video Surveillance

"Steven M. Bellovin" <smb@cs.columbia.edu> Fri, 28 February 2014 17:30 UTC

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From: "Steven M. Bellovin" <smb@cs.columbia.edu>
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Date: Fri, 28 Feb 2014 17:25:33 +0000
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References: <CAMRcRGQapsgWfgjXLYWDjZg4h6p6fOh7F8JSUHBoForVLqQwwA@mail.gmail.com> <CF5FE91B-6A91-4072-BBE6-62C268F33E19@isoc.org> <CAMRcRGQyPWrW8h+EZTCxfMf08LPCx6EXZSxb15QP-Libh+8OvA@mail.gmail.com> <D98FB8B5-4145-44FA-8724-0E140BEBFD88@cs.columbia.edu> <5CDDE895-C076-4D39-884A-F6D8DCFDC740@isoc.org> <7B185B5A-5DA2-447B-B6FB-888F98F95439@isoc.org>
To: Robin Wilton <wilton@isoc.org>
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Cc: "<strint-attendees@lists.i1b.org>" <strint-attendees@lists.i1b.org>, perpass <perpass@ietf.org>
Subject: Re: [Strint-attendees] [perpass] GHCQ Webcam Video Surveillance
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I made the same assumption until others corrected me.

On Feb 28, 2014, at 5:17 PM, Robin Wilton <wilton@isoc.org>; wrote:

> With apologies for one further mail on this topic... Steve is right, and I stand corrected.
> 
> As far as I can determine, the light sensor on a MacBook Air (well, mine, at least) is about 1-4mm to the left of the webcam aperture in the screen surround. 
> 
> This means that you can block the webcam without interfering with the automatic screen brightness function - but you need to position your webcam-blocker as carefully as in Steve's picture, and from the right of the lens aperture.
> 
> Serves me right for (a) making assumptions and (b) using my left thumb to occlude the lens. If I had used my right thumb, I wouldn't have made the same assumption (!)
> 
> Thanks Steve!
> 
> Robin 
>  
> On 28 Feb 2014, at 16:52, Robin Wilton wrote:
> 
>> Apologies - I should have been more specific... my Macbook Air doesn't have a separate light sensor... it's in the same orifice as the camera lens.
>> 
>> R
>> 
>> Robin Wilton
>> Technical Outreach Director - Identity and Privacy
>> Internet Society
>> 
>> email: wilton@isoc.org
>> Phone: +44 705 005 2931
>> Twitter: @futureidentity
>> 
>> On 28 Feb 2014, at 14:54, Steven M. Bellovin wrote:
>> 
>>> 
>>> On Feb 28, 2014, at 2:41 PM, Suhas Nandakumar <suhasietf@gmail.com>; wrote:
>>> 
>>>> 
>>>> (incidentally, if you're using a Mac and you cover the webcam lens, you'll need to turn off the automatic screen-dimming function. System Preferences -> Displays )
>>>> 
>>> 
>>> Not really -- the light sensor on many Macbooks, at least, is to the left of the camera lens.  This just came up on Twitter; here's my set-up at https://twitter.com/SteveBellovin/status/439412122410184704.  (I don't want to clog the list with a large picture attachment.)  Yes, it works, and if you find me here I'll show you what happens if I move the slide to the left a bit more.
>>> 
>>> 
>>> 		--Steve Bellovin, https://www.cs.columbia.edu/~smb
>>> 
>>> 
>>> 
>>> 
>>> 
>> 
> 
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		--Steve Bellovin, https://www.cs.columbia.edu/~smb