If you're using Internet Explorer to browse the Web and wondering why you can't access Google, there's a reason — your computer might think it's harboring malware. Two of Microsoft's anti-virus programs, Microsoft Security Essentials and its business-market sibling Microsoft Forefront, have been mistakenly flagging Google.com as malicious, leaving millions of customers unable to get to the world's most visited website.
MSNBC
I do not think it was a mistake, it was intentional. That is competition war for you not knowing that the Microsoft market will be affected as well...