I used to use and train people in computer graphics and using CG software.
At my new job, I got bored, so I wanted to use one of the drawing softwares.
Well, it had a couple of sample pictures, but I wanted to find some better pictures to use.
So, I used the search facility all PC's have and searched the entire network for pictures with the proper file extension.
Well, I found many.
Point is, if you know what file extensions are used (and kids know) for image files, it is easy to search for them.