Yep just from images (and Google) - I examined one of the images from the post at a higher resolution (by clicking on it) and took a look at the map on the right-hand side.

It was a map of Thailand, so that gave me the type of restaurant. From there it was just a simple Google query combining that knowledge with the URL structure revealed in the blog post:

http://www.google.co.uk/search?q=thai+restaurant+locationid%...

Then it was just a case of working through the list of possibilities (it was second on that list) :-)

Good searching. Looks like you've found quite a few more vulnerable sites too.

I would wager to say a large majority of .asp sites out there are vulnerable to these types of issues.

Most were coded before common sanitization and security practices were observed during dev, not to mention built in to frameworks.

Obviously he just zoomed in and kept saying "enhance image" to his computer until the answer was revealed in a tiny shadow on one of the pixels...

Damn this thing and it's ability to only upvote once!

Screenshot + TinEye?