On a quick glance, I assumed there was a page error.
Their page works if you take the time to read it, but I assume most non technical users will open the page, see the page error, assume the page is down for technical reasons, and go about the rest of their day.
Edit: Actually, I don't want to change it. I don't think our readers will read three words and skip the explanation. I think much more highly of them than that.
Here's a suggestion: format the page as if it was taken down by the government. Something like this: http://corecorina.files.wordpress.com/2011/04/rippoker.jpg
That said, I do agree that it would be more effective sans-503 error.