FWIW Reading the source code the thumbnails and mouse-over images are pulled directly from iStock and not hosted on their server.
href="catalog/category/view/order/price/dir/asc/limit/all/id/3/?imageId=6608426&imageTitle=Abstract Waterfall">
<img src="http://www1.istockphoto.com/file_thumbview_approve/6608426/1/" alt="Abstract Waterfall" onmouseover="showtrail('http://www1.istockphoto.com/file_thumbview_approve/6608426/2/','Abstract+Waterfall',' ','5.0000',
href="catalog/category/view/order/price/dir/asc/limit/all/id/3/?imageId=6608426&imageTitle=Abstract Waterfall">
<img src="http://www1.istockphoto.com/file_thumbview_approve/6608426/1/" alt="Abstract Waterfall" onmouseover="showtrail('http://www1.istockphoto.com/file_thumbview_approve/6608426/2/','Abstract+Waterfall',' ','5.0000',



