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

Robin Wilton <wilton@isoc.org> Fri, 28 February 2014 17:17 UTC

Return-Path: <wilton@isoc.org>
X-Original-To: strint-attendees@lists.i1b.org
Received: from na01-bn1-obe.outbound.protection.outlook.com (mail-bn1lp0141.outbound.protection.outlook.com [207.46.163.141]) by diego.dreamhost.com (Postfix) with ESMTP id 03D7648C1C for <strint-attendees@lists.i1b.org>; Fri, 28 Feb 2014 09:17:42 -0800 (PST)
Received: from BY2PR06MB647.namprd06.prod.outlook.com (10.141.223.153) by BY2PR06MB092.namprd06.prod.outlook.com (10.242.43.28) with Microsoft SMTP Server (TLS) id 15.0.883.10; Fri, 28 Feb 2014 17:17:40 +0000
Received: from BN1PR06MB119.namprd06.prod.outlook.com (10.255.204.25) by BY2PR06MB647.namprd06.prod.outlook.com (10.141.223.153) with Microsoft SMTP Server (TLS) id 15.0.883.10; Fri, 28 Feb 2014 17:17:38 +0000
Received: from BN1PR06MB119.namprd06.prod.outlook.com ([169.254.14.78]) by BN1PR06MB119.namprd06.prod.outlook.com ([169.254.14.78]) with mapi id 15.00.0883.010; Fri, 28 Feb 2014 17:17:37 +0000
From: Robin Wilton <wilton@isoc.org>
To: "<strint-attendees@lists.i1b.org>" <strint-attendees@lists.i1b.org>, perpass <perpass@ietf.org>
Thread-Topic: [Strint-attendees] [perpass] GHCQ Webcam Video Surveillance
Thread-Index: AQHPNI/K/RsfJPbhNkCqh9PN50ZBU5rKut0AgAACYYCAAAOxAIAAIOKAgAAHEYA=
Date: Fri, 28 Feb 2014 17:17:36 +0000
Message-ID: <7B185B5A-5DA2-447B-B6FB-888F98F95439@isoc.org>
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>
In-Reply-To: <5CDDE895-C076-4D39-884A-F6D8DCFDC740@isoc.org>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach: yes
X-MS-TNEF-Correlator:
x-originating-ip: [94.174.34.240]
x-forefront-prvs: 0136C1DDA4
x-forefront-antispam-report: SFV:NSPM; SFS:(10019001)(428001)(199002)(189002)(252514010)(377454003)(24454002)(65816001)(93516002)(33656001)(54316002)(19580405001)(94946001)(56776001)(86362001)(46102001)(51856001)(66066001)(19580395003)(54356001)(83322001)(85852003)(94316002)(49866001)(63696002)(83072002)(76786001)(69226001)(92566001)(47976001)(76796001)(53806001)(87936001)(92726001)(77096001)(80022001)(93136001)(85306002)(90146001)(74876001)(81686001)(87266001)(2656002)(74706001)(82746002)(16236675002)(4396001)(77982001)(81816001)(95666003)(79102001)(31966008)(81342001)(95416001)(50986001)(74366001)(81542001)(83716003)(80976001)(76482001)(36756003)(56816005)(15975445006)(47446002)(74502001)(74662001)(47736001)(59766001)(491001); DIR:OUT; SFP:1102; SCL:1; SRVR:BY2PR06MB647; H:BN1PR06MB119.namprd06.prod.outlook.com; CLIP:94.174.34.240; FPR:ECCFC1E4.AEA25BE1.E1F3BDAF.8462FC60.202EE; PTR:InfoNoRecords; A:1; MX:1; LANG:en;
received-spf: None (: isoc.org does not designate permitted sender hosts)
Content-Type: multipart/signed; boundary="Apple-Mail=_A9699B26-4193-4EE4-A6FF-D9EF766EB117"; protocol="application/pkcs7-signature"; micalg=sha1
MIME-Version: 1.0
X-OriginatorOrg: isoc.org
Subject: Re: [Strint-attendees] [perpass] GHCQ Webcam Video Surveillance
X-BeenThere: strint-attendees@lists.i1b.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: STRINT Workshop Discussion List <strint-attendees-i1b.org>
List-Unsubscribe: <http://lists.i1b.org/options.cgi/strint-attendees-i1b.org>, <mailto:strint-attendees-request@lists.i1b.org?subject=unsubscribe>
List-Archive: <http://lists.i1b.org/pipermail/strint-attendees-i1b.org>
List-Post: <mailto:strint-attendees@lists.i1b.org>
List-Help: <mailto:strint-attendees-request@lists.i1b.org?subject=help>
List-Subscribe: <http://lists.i1b.org/listinfo.cgi/strint-attendees-i1b.org>, <mailto:strint-attendees-request@lists.i1b.org?subject=subscribe>
X-List-Received-Date: Fri, 28 Feb 2014 17:17:42 -0000

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
>> 
>> 
>> 
>> 
>> 
>