Especially when the images are scraped off the CC-BY and CC-BY-SA Flickr streams.
That was something I noticed the other day. An anon replaced the infobox image on Veganism with a close-up shot of a woman's genitals and a vibrator. I looked to see who had uploaded it and it said Flickr upload bot. So is there a bot that uploads all cc images from Flickr indiscriminately?
Apparently a bot does the work, but a human has to ask for them.
http://commons.wikimedia.org/wiki/User:Flickr_upload_bot
Chris