[HacktionLab] Wake up!!! .... and change you printer!

[Atom Juggler]

he's some more old news.
they can find out wot device ie: phone took a picture by the info on the file that you need special software to see it..

Digital cameras and image manipulation programs add hidden data to
 JPEG files. For different reasons, one might want to remove 
these data before publishing the files on the Internet.

The JPEG file format allows it to embed additional information 
called "metadata" in the file header. (Other image file formats 
can contain metadata, too.) The purpose of these metadata is to 
provide additional and useful information along with the picture.
Image manipulation programs and especially digital cameras take 
advantage of this feature.


Should Metadata Be Removed?

If you intend to publish JPEG files on the Internet, 
you might want to remove all metadata to reduce the file size of 
the JPEG files. Depending on what kinds of metadata are stored in 
the file, the reduction can range between a few bytes and several 
kilobytes. For example, if you have a website with metered 
bandwidth or if you have visitors with dialup modems, you might 
be interested in saving as much bytes as possible.

Another reason why you might want to consider removing all 
metadata beforehand is that metadata can give away potentially 
sensitive information. This information can mean a thread to your 
privacy or to other legitimate interests (e. g. the interest of 
journalists to protect their sources). The following fictitious 
and real-life examples try to illustrate the problematic nature 
of metadata information:

How to Remove Metadata

If you want to remove metadata from JPEG files, you should keep 
in mind that these data can provide useful information (such as 
focal length, shutter speed, etc.). Therefore, you should never 
remove them from your original pictures. Instead, you should make 
a copy of the picture you want to publish and then remove the 
metadata from this copy.

Several software tools support the removal of metadata. A 
recommendable one is jhead. It is a free open source program 
that runs on a variety of operating systems (Windows/Linux/BSD/Mac). 
Because jhead is a command line tool, it is particularly suitable 
to be used with batch files.

Less experienced users should adhere to this step-by-step guide 
(Windows):

Create the directory C:\jpeg.
Copy all pictures whose metadata you want to remove to C:\jpeg.
Download the program file jhead.exe to C:\jpeg.
Click on "Start" and then "Execute...".
Windows 95/98/Me: Type command.com and click on "OK".
Windows NT/2000/XP: Type cmd.exe and click on "OK".
Change to C:\jpeg. To do so, type the following (the words in 
brackets are instructions to be executed, not to be typed):
c:  (press return)
cd\  (press return)
cd jpeg  (press return) 
To remove all metadata of all JPEG files in "C:\jpeg", type:
jhead -purejpg *  (press return)
If you prefer programs with a graphical user interface, you should 
try IrfanView. It is a free program for Windows that allows you to 
view and edit images. Besides IrfanView itself, you need the plug-in 
"Lossless JPG Transformations". More detailed information about how 
to install this plug-in can be found on IrfanView's homepage.

Full artical here but for some reason wanted to open in google chrome only http://www.google.co.uk/url?sa=t&source=web&cd=9&ved=0CC4QFjAI&url=http%3A%2F%2Fsites.google.com%2Fsite%2Fnetzreport2%2Fhidden_data_in_jpeg_files.html&rct=j&q=hidden%20information%20in%20photo&ei=KqrWTNzQLsK4jAelv_2tCQ&usg=AFQjCNFn-oFmv4yeDCq4rP-tc0G_r5jGkg&cad=rja

seeing im on a yellow card, this is a tech posting :P 

> Date: Wed, 3 Nov 2010 17:40:30 +0000
> From: startx at plentyfact.org
> To: hacktionlab at lists.psand.net
> Subject: Re: [HacktionLab] Wake up!!! .... and change you printer!
> 
> On Wed, 03 Nov 2010 17:29:06 +0000
> Mike Harris <mike at mbharris.co.uk> wrote:
> 
> > Conspiracy or not?
> > 
> > At least it's a tech posting :P
> > 
> > http://seeingyellow.com/
> > 
> > 
> 
> its not a conspiracy, its a well known technique by some printer
> manufacturer to (potentially) track faked money, vouchers, tickets etc.
> 
> see http://www.eff.org/issues/printers
> 
> the eff has also published a list of printers who do not use this
> method, but however those might use other methods:
> 
> http://www.eff.org/pages/list-printers-which-do-or-do-not-display-tracking-dots
> 
> startx
> 
> _______________________________________________
> HacktionLab mailing list
> HacktionLab at lists.psand.net
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