It should be no surprise that the security of the site is going to come under some scrutiny. The Register already has one article about the issues someone found.
I took a few minutes and check the site out myself and found another issue.
The interesting part is this:
If we decode this base64 encoded string, we get this:
So, lets encode our own string and create a new URL that looks like this:http://www.hackiswack.com/index.php?option=com_jfbconnect&task=logout&return=aHR0cDovL3d3dy55b3V0dWJlLmNvbS93YXRjaD92PW9IZzVTSllSSEEw
Yeah. That would be yet another RickRoll...