The FEMA death camp conspiracy theories popped up almost as fast as FEMA was created. Sadly there are some freepers who believe the garbage.
Here's what I found while digging around.
http://afrikan.i-dentity.com/wwwboard/messages/2038.html
http://www.tpo.net/conspiracy/FEMA.shtml
http://www.sharelynx.com/papers/holocaust.php
That's because they want to believe it's true. They love these conspiracy theories and freely spread them around. Some people just seem to have a need for it.