On 28/10/2014 16:54, A. Beck. wrote:

How much EXIF information is tracked by photo sharing sites?
http://regex.info/exif.cgi

I often post photos to photo-sharing sites, whether for the
purpose of social networking (pinterest, facebook, etc)
or for Usenet posts (tinypic, flickr, etc) or for personal
sharing (iCloud, dropbox, google drive, etc).

The EXIF, as you know, can reveal exactly where and when
the photo was taken, and even what camera was used, and, of
course, the time and date, etc, the combination of which could
easily reveal intensely personal information.

You have to assume that any metadata like EXIF or text you post into the
internet will be scanned by malevolent agents now or in the future.

Basically if you are worried strip the EXIF data off and/or resample the
image down to a smaller size and watermark it. That way when someone
attempts to use your copyright images without permission you can if
necessary stamp on them. I have only done it a couple of times.

Normally I will grant permission and provide the full resolution image
on condition that I get a copy of the book that is using it. It is
madness to make the full resolution of a valuable image available free.

When I DOWNLOAD those pictures, generally (always?) the
EXIF information seems to be stripped out.

And probably resampled and compressed to a standard canonical JPEG
encoding as opposed to the custom qtables out of the camera.

But ... how much of that personal EXIF information is retained by
the web site (and used for their possibly nefarious purposes)?

Probably all of it so be careful what you upload. Also read the small
print very carefully many of these photo "sharing" sites will lay claim
to them gaining your image copyright hidden in their terms of use.

Same sort of issues with facebook etc where people often provide enough
information to allow thieves to target empty houses whilst the owners
are mindlessly tweeting and facebooking their holiday snaps.

--
Regards,
Martin Brown