Since many investigators are searching for additional info it seems that one avenue might be overlooked. Although some are using reverse image search tools like the following

https://images.google.com/ https://www.tineye.com/

I have not seen anyone using exif data viewer's on individual photos.

Here is an example

This podesta email has a strange photo attachment for no apparent reason (Could just be innocent photo) but lets look a little deeper.

20150827_071810_s.jpg 925.17 KiB image/jpeg

https://www.wikileaks.org/podesta-emails/emailid/20741#searchresult

Although this pic has no GPS data... Some DO

But we can still tell that the photo was taken with a Samsung galaxy S5 cellphone on 8/27/2015 @ 08:27

http://metapicz.com/#landing

EXIF DATA

Make SAMSUNG Model SM-G900P Orientation Horizontal (normal) XResolution 72 YResolution 72 ResolutionUnit inches Software G900PVPU3BOG1 ModifyDate 2015:08:27 07:18:09 FNumber 2.2 ExposureProgram Program AE ExifVersion 0220 DateTimeOriginal 2015:08:27 07:18:09 CreateDate 2015:08:27 07:18:09 ComponentsConfiguration Y, Cb, Cr, - MaxApertureValue 2.2 MeteringMode Center-weighted average FocalLength 4.8 mm FlashpixVersion 0100 ColorSpace sRGB ExifImageWidth 1494 ExifImageHeight 2293 ExposureMode Auto WhiteBalance Auto FocalLengthIn35mmFormat 31 mm SceneCaptureType Night

The regex.info website is not functioning but

Here is an example of some DATA that can be retrieved from a pic..

http://regex.info/imageinfo.cgi?url=http%3A%2F%2Fregex.info%2Fi%2F_JEF1348.jpg

Thought this might help some investigators reveal additional info that may be getting overlooked...

Please post your findings and additional tools to expose additional hidden MetaData

Happy Hunting