The problem is due to the GFY user Viencarl
http://www.gofuckyourself.com/member.php?u=91378 posting links to images that are in a members only area at motleycrow.com
For example of one of Viencarl's posts causing problems see
http://www.gofuckyourself.com/showthread.php?t=821042 Post #11
The poster likely isn't even aware their image links are causing problems.
Ron