Disclaimer:
This is not an advertisement to any other browsers.

Serious security flaw found in IE (Internet Explorer):
http://news.bbc.co.uk/2/hi/technology/7784908.stm

"Microsoft is continuing its investigation of public reports of attacks against a new vulnerability in Internet Explorer," said the firm in a security advisory alert about the flaw.

So be in the safer side, don't use IE…
Use Open Source alternatives…!

(Thanks Ramanan)