View this link:

http://rawstory.com/news/2008/Satellite_images_show_ethnic_cleansing_source_0919.html

I have no idea how reputable this is but it seemed worth posting.

“By the launch of the surge, many of the targets of conflict had either been killed or fled the country, and they turned off the lights when they left,” geography professor John Agnew of the University of California Los Angeles, who led the study, said in a statement.

“Essentially, our interpretation is that violence has declined in Baghdad because of intercommunal violence that reached a climax as the surge was beginning,” said Agnew, who studies ethnic conflict.