You'll sometimes go to an IT group and ask about support for Firefox, Safari (etc, etc) - and get the response that "we're a Microsoft shop". Typically infuriating, but you probably never thought of it as being dangerous - until now:

What is surprising, however, is the fact that the Federal Emergency Management Agency's (FEMA) online registration site for disaster help is Internet Explorer-only. While anyone can browse the site, users of non-IE browsers will find this message waiting for them when they attempt to register.

In order to use this site, you must have JavaScript Enabled and Internet Explorer version 6. Download it from Microsoft or call 1-800-621-FEMA (3362) to register.

With all of FEMA's other problems at the moment, I doubt that this one is high on the radar. On the other hand, would you want to be the IT manager who had to explain "we couldn't take donations from that large group there, because they insisted on using Macs" ?

Likewise, in a business situation, do you want to be the IT manager who has to explain the lost prospects - who were lost because your site turned them away with a message like the one above? I know I wouldn't.

Hat tip Jonathan Schwartz.