Well, because hundreds of thousands of web servers are feeding up exploits aimed at you.
A web search showed 233,000 pages containing the string ardoshanghai.com/s.js, just one of many web addresses exploiting a weakness in the way IE's data-binding function works. Most of the attacks silently install keylogging software as soon as a victim surfs to a site carrying the exploit. Once installed, the software steals login credentials for online games.And that's only one piece of malware. There are likely millions of web servers targeting your Internet Explorer browser.
Since Internet Explorer is teh br0ken, so why not change to a safer browser?
UPDATE 18 December 2008 13:05: Very interesting discussion in the comments at Slashdot.