not2easy - 12:32 am on Dec 20, 2012 (gmt 0)

"Mozilla/5.0 (compatible; bingbot/2.0; +h tt p://www.bing. com/bingbot.htm)" is the bingbot and "msnbot-media/1.1 (+h tt p://search.msn. com/msnbot.htm)" is the MSNBot that is currently grabbing images but is supposed be retired at some point.
_{(Using spaces to delink.)}
Since they are compliant, blocking images in robots.txt is all you would need to do to cover blocking images from them both (along with all other compliant bots).

I use:
Disallow: /*.gif$
Disallow: /*.jpg$
Disallow: /*.png$

and the bing site says they follow wildcards.