Submitted via IRC for Bytram
Facebook Knows How to Track You Using the Dust on Your Camera Lens
In 2014, Facebook filed a patent application for a technique that employs smartphone data to figure out if two people might know each other. The author, an engineering manager at Facebook named Ben Chen, wrote that it was not merely possible to detect that two smartphones were in the same place at the same time, but that by comparing the accelerometer and gyroscope readings of each phone, the data could identify when people were facing each other or walking together. That way, Facebook could suggest you friend the person you were talking to at a bar last night, and not all the other people there that you chose not to talk to. Facebook says it hasn't put this technique into practice.
[...] Patents filed by Facebook that mention People You May Know show some ingenious methods that Facebook has devised for figuring out that seeming strangers on the network might know each other. One filed in 2015 describes a technique that would connect two people through the camera metadata associated with the photos they uploaded. It might assume two people knew each other if the images they uploaded looked like they were titled in the same series of photos—IMG_4605739.jpg and IMG_4605742, for example—or if lens scratches or dust were detectable in the same spots on the photos, revealing the photos were taken by the same camera.
[...] The technological analysis in some of the patents is pretty astounding, but it could well be wishful thinking on Facebook's part.
Vera Ranieri, an attorney at the Electronic Frontier Foundation who focuses on intellectual property, hasn't reviewed these specific patents but said generally that the U.S. Patent Office doesn't ensure that a technology actually works before granting a patent.
(Score: -1, Offtopic) by Anonymous Coward on Monday January 07 2019, @11:02AM (3 children)
Linux and license revocation, Explained in American vernacular:
Video: http://openload.co/f/mT_AH3xmIUM/TruthAboutLinuxandGPLv2__.mp4 [openload.co]
Audio: http://ufile.io/sdhpl [ufile.io]
Enjoy.
(Score: 1, Offtopic) by Runaway1956 on Monday January 07 2019, @11:52AM (2 children)
I really don't think that dude knows what he is talking about. Just because he speaks in the crude vulgar language we hear on the streets and on construction sites, you figure he knows what he's talking about? "American vernacular"??? WTF?
I've never heard of anyone rescinding a free license. BSD, or GPL, or any other. The ONLY free license I've ever heard of that was rescinded was public domain. Don't remember exactly what it was, not bothering to look it up, but something or other entered the public domain, then bribes were paid to put a copyright on it again.
If you're banking on some street nigga making case law for you, I expect you'll be terribly disappointed. Probably just some hired actor - and probably some white dude at that.
(Score: 0) by Anonymous Coward on Wednesday January 09 2019, @07:56AM
A gratuitous license, without an attached interest, is revocable.
Did you pay for a license for X intellectual property?
No?
Then the permission to use that IP can be rescinded, since you have no secured any interest in it against the owner.
It's just how it is.
It hasn't been done often because no one went after the programmers.
But now they are with the speech codes.
There have been lengthy discussions on this, including published papers specifically about the GPLv2.
It's a gratuitous license.
(Score: 0) by Anonymous Coward on Wednesday January 09 2019, @08:00AM
>If you're banking on some street nigga making case law for you, I expect you'll be terribly disappointed. Probably just some hired actor - and probably some white dude at that.
You people simply do not accept it when lawyers explain to you that gratuitous licenses are revocable by the grantor.
You just DO NOT accept it.
So we have a "street nigga" explain it to you in your own language.
And that's just not good enough either...
(Score: 3, Interesting) by Anonymous Coward on Monday January 07 2019, @11:52AM (4 children)
Not only dust, but also pixel sensitivity, threshold and "bad pixels" can be used to fingerprint image sensors.
Was more evident with analog cameras. And are easy to visually appreciate in low light conditions.
Actual digital sensors and compression artifacts tend to mask the pixel variance to the naked eye, but not to filtering algorithms given that enough image frames from a given sensor are available.
Astro sensors are chilled and calibrated to reduce noise and avoid some of these artifacts.
If you still have your old camcorder and a CRT tv try it yourself. Connect the cam to the TV via s-vhs cable, put the lens lid on and in the tv raise the brightness and adjust the contrast until you see the fixed pixel pattern of you sensor. Many image sensors I've checked look like you are watching a starry night with a few really bright spots.
(Score: 2) by SpockLogic on Monday January 07 2019, @01:51PM (3 children)
Note to self :- Clean lens frequently.
Overreacting is one thing, sticking your head up your ass hoping the problem goes away is another - edIII
(Score: 4, Insightful) by nitehawk214 on Monday January 07 2019, @02:14PM (2 children)
Which means you will eventually scratch the lens, making you more identifiable.
"Don't you ever miss the days when you used to be nostalgic?" -Loiosh
(Score: 3, Informative) by Anonymous Coward on Monday January 07 2019, @06:42PM (1 child)
If you clean your lenses properly they will not get scratched no matter how frequently you clean them.
Normal glass is about a 6 on the Mohs scale, harder glasses such as borosilicate glass are about 8. These materials are actually quite difficult to scratch. Sure, if you get your lens paper contaminated with sapphire dust or something you might manage to scratch borosilicate glass with it. Lens elements are sometimes are made with more exotic materials like fluorite (about 4 on the Mohs scale, more easily scratched) for its different optical properties, but those would not typically be used on the outer elements that need cleaning.
(Score: 1) by nitehawk214 on Thursday January 10 2019, @06:05PM
Actually all non-shit lenses have coatings that are even harder than the glass. However, the more times you clean it, the more opportunities for a piece of dirt to get on it and dragged across.
"Don't you ever miss the days when you used to be nostalgic?" -Loiosh
(Score: 3, Interesting) by Runaway1956 on Monday January 07 2019, @12:04PM (9 children)
I don't know how prevalent it was, but hardware was "fingerprinted" long ago. Firearms, everyone knows about, right? Infrastructure generators were apparently fingerprinted - different generators/alternators around the country sounded different, so they could be identified in recordings. (Think ransom demands and such - FBI can tell you roughly where the recording was made, among other things. https://en.wikipedia.org/wiki/Electrical_network_frequency_analysis [wikipedia.org]
Sure, if you don't clean your lenses, you'll leave a "watermark" on all of your photos. A scratch, or other imperfection in the lens - even something that you can't see. There could even be a digital watermark embedded in the lens - maybe we should ask the manufacturers?
But, with all the metadata that digital photos are stamped with today, this physical fingerprinting seems a bit redundant.
(Score: 1, Interesting) by Anonymous Coward on Monday January 07 2019, @01:36PM (8 children)
But people know about that metadata, and it is documented how that metadata is stored, and thus it is easy to get rid of it if you want to. The physical fingerprinting may be harder to remove (OK, dust on your lens generally is pretty easily removed, as long as it is outside; however the very fact that you are regularly cleaning your lens in a world where most people don't may also help to identify you — not to mention that you are more likely to introduce characteristic scratches that way).
(Score: 2, Insightful) by nitehawk214 on Monday January 07 2019, @02:17PM
I suppose if you only use the camera for the nefarious purpose, there is no way to fingerprint it physically.
Which seems like it should go without saying. Use a burner phone for illegal activities.
"Don't you ever miss the days when you used to be nostalgic?" -Loiosh
(Score: 3, Interesting) by fyngyrz on Monday January 07 2019, @03:23PM (6 children)
One of the very first things I implemented in my image processing software was control over the metadata. I figure that when someone shares a chunk of data like an image, (a) they ought to be able to know the details of what it is they are sharing, and (b) they ought to be able to control those details.
For metadata that is broken - such as EXIF - I simply throw it out:
--
Have an urge to follow the masses? Careful:
Sometimes, the "m" is silent.
(Score: 5, Informative) by mmh on Monday January 07 2019, @05:40PM (5 children)
I suspect many on this site know about the "hidden" meta-data in most image formats, but if not, a quick overview.
The command exiftool can be used to view most metadata on an image, and despite it's name, more than just EXIF data.
Images can contain some truly scary data, as the parent post points out (I've modified the GPS location below):
$ exiftool IMG_0100.jpg
...SNIP...
Make : Apple
Camera Model Name : iPhone XS Max
...SNIP...
Acceleration Vector : -0.9981475478 0.01597352512 0.04706366733
...SNIP...
Lens Info : 4.25-6mm f/1.8-2.4
Lens Make : Apple
Lens Model : iPhone XS Max back dual camera 4.25mm f/1.8
...SNIP...
GPS Latitude Ref : North
GPS Longitude Ref : West
GPS Altitude Ref : Above Sea Level
GPS Time Stamp : 03:41:12
GPS Speed Ref : km/h
GPS Speed : 0.06613545865
GPS Img Direction Ref : True North
GPS Img Direction : 136.7193747
GPS Dest Bearing Ref : True North
GPS Dest Bearing : 136.7193747
GPS Date Stamp : 2018:12:31
GPS Altitude : 1373.2 m Above Sea Level
GPS Date/Time : 2018:12:31 03:41:12Z
GPS Latitude : 44 deg 33' 55.33" N
GPS Longitude : 111 deg 55' 5.44" W
GPS Position : 44 deg 33' 55.33" N, 111 deg 55' 5.44" W
GPS Horizontal Positioning Error: 6.32029273 m
The utility ImageMagick (http://www.imagemagick.org/ [imagemagick.org]) provides a very easy way to remove all non-image data from all supported image formats:
$ convert -strip IMG_0100.jpg IMG_0100s.jpg
$ exiftool IMG_0100s.jpg
... All identifying information removed ...
(Score: 3, Insightful) by pvanhoof on Monday January 07 2019, @06:08PM (2 children)
Sure, and this information can also be used for good. If you for example have tracker on your GNOME desktop, tracker's metadata extraction will turn all that data into desktop searchable data. Meaning that you can find your files with it using SPARQL queries.
And if you don't like that, you can turn it off.
Basically you can form queries like: give me all pictures that I made with my iPhone while I was in Paris.
https://gitlab.gnome.org/GNOME/tracker-miners/blob/master/src/tracker-extract/tracker-extract-png.c#L516 [gnome.org]
There is nothing 'strange' about the fact that metadata is contained in files. It can be quite useful. There is little scary about it.
(Score: 2) by fyngyrz on Monday January 07 2019, @06:57PM (1 child)
That's correct.
Also correct.
That depends entirely on the use case. If you don't understand that, you should start being scared immediately.
--
Some drink from the fountain of knowledge. Others gargle.
(Score: 3, Funny) by maxwell demon on Monday January 07 2019, @07:34PM
Metadata that is well-documented, easy to read and easy to change and/or remove is not very scary. It is, of course, something you have to take into account when handling those images.
It gets scary if you don't know the existence of data, you can't easily check it, or you can't easily remove it.
Note that for most holiday photos the GPS coordinates/camera direction don't reveal anything that isn't revealed also in the image itself. If you photographed the White House, it is quite obvious that you weren't in New York.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 1) by fustakrakich on Tuesday January 08 2019, @05:26AM
Make : Apple?
Ah, then don't worry. What goes in your iPhone stays in your iPhone...
La politica e i criminali sono la stessa cosa..
(Score: 2) by Reziac on Tuesday January 08 2019, @06:17AM
Or for Windows, a marvelous tool, JPEGsnoop.
https://www.impulseadventure.com/photo/jpeg-snoop.html [impulseadventure.com]
https://github.com/ImpulseAdventure/JPEGsnoop [github.com]
And there is no Alkibiades to come back and save us from ourselves.
(Score: 2) by Nuke on Monday January 07 2019, @05:25PM (5 children)
Can someone please explain to me what is the advantage to FB of knowing who I was talking or walking with (unless it is with intent to blackmail, but presumably even FB would not go that far) ?
(Score: 5, Funny) by DannyB on Monday January 07 2019, @07:11PM
I would mod you Insanely Naive, but alas no such mod.
FB would steal your vital organs and justify it as their sacred duty to increase shareholder value if they thought they could make a buck by doing so. Just like any publicly tiraded corporation.
The lower I set my standards the more accomplishments I have.
(Score: 2) by maxwell demon on Monday January 07 2019, @07:40PM (2 children)
You are often together with John Smith, outside working hours. So you're likely friends with John Smith. John Smith has birthday soon. So you're likely going to buy a birthday present for him. Facebook knows (or thinks it knows) what John Smith likes from his profile data. Facebook also infers how much you are likely willing to spend, based on your Facebook profile. Suddenly you see many ads for potential presents for John Smith in that price range.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 0) by Anonymous Coward on Monday January 07 2019, @09:38PM
That's how you maximize shareholder value. And get to charge more for the "targeted" ads.
(Score: 2) by krishnoid on Tuesday January 08 2019, @12:59AM
Are you now, or have you ever been a member, of the John Smith party of the United States? [wikipedia.org] And do you know any people who are members of this party?
(Score: 0) by Anonymous Coward on Monday January 07 2019, @10:19PM
tl;dr: It's how Trump got elected. What's in it for FB? Payment, obviously.
(Score: 3, Insightful) by Anonymous Coward on Monday January 07 2019, @06:25PM (2 children)
This is likely an accurate description of what is happening here. Many companies, and I doubt Facebook is any exception, give staff bonuses for filing patent applications and/or receiving patent grants. Neither the companies nor the US patent office give a shit whether the the invention is even possible to make. They only care about quantity.
Normal levels of dust on the surface of a camera lens does exactly diddly squat to the image. Pretty much the only effect of dust on the lens elements is the reduction in overall light level reaching the sensor, and this effect will be completely dominated by the actual lighting of your scene.
Even significant scratches on lens elements will produce basically the same (non-)effect.
(Score: 1, Interesting) by Anonymous Coward on Monday January 07 2019, @06:51PM
Came here to say the same thing, dust on the lens does not form an image in the sensor plane.
(Score: 0) by Anonymous Coward on Thursday January 10 2019, @03:53PM
You're dangerously wrong! Just because a human eye can't see it doesn't mean the signal isn't there. I can make the least significant bit of the saturation channel encode text and you'd never see it. In this instance, the sensor dust gaussian can detected from a video stream and de-convolved to it's on-sensor shape pretty easily.
Look up the math behind "unsharp mask" and it should be evident why FB's patent is, in fact, technically quite doable.