But, why we need to block IE6? Well, IE6 was released on August 27, 2001 and no longer maintained by Microsoft since it. Therefore IE 6 can't provide the same web experience that modern browsers can. IE6 also have so many bugs and security holes issues that can be very dangerous for your PC.
For many web developers, continued support of IE 6 means that they can't optimize their interfaces or provide an enhanced customer experience in their apps. Supporting IE 6 means slower progress, less progress, and, in some places, no progress. They want to make sure the experience is the best it can be for the vast majority of their customers, and continuing to support IE 6 holds they back.
In the recently years, web developers joined at various social movements to subvert the power of this Microsoft's browser and give awareness to the users to start using modern browsers or update their IE6 browser to the newest one (IE7+).
No Internet Explorer 6! is another example of campaign from Apa Dong (dot) Org. For demo, you can try open my blog or this page using IE6 and see what happen.