Thousands of random images within iPhoto library
I'm attempting to troubleshoot why thousands of images that appear in my iPhoto library were not taken by me, or imported via iPhone. These images are generally low resolution images ranging from pictures of foods, flags, sports emblems, furniture, website icons and random pictures of people. I assume they are originating from the internet and somehow being imported into the iPhoto library. There are approximately 400 legitimate photos and a total of 7,378 images altogether. These images are inserted throughout the library randomly, making it impossible to delete them easily. No matter how many times they are deleted, more just appear.
I have repaired permissions, repaired and rebuilt the database to no avail. I would really appreciate any help on this matter.
Thank you in advance.
MacBook Pro, Mac OSX 10.6.8
iPhoto '09 version 8.1.2 (424)
MacBook Pro, Mac OS X (10.6.8)