tedster - 5:26 pm on Feb 3, 2011 (gmt 0)
When Google finds what it thinks are organic spam issues that can affect Adsense membership - but as far as I know the site just gets kicked out of the program if action is taken, not depressed. I also don't think that the connection is automated.
Did you see that Google now has a Webmaster Forum for Image Search [google.com]? I'm hoping to at least monitor the Q&A in there from time to time, to get some more official input about how Images work.