I’ll bet the Library of Congress never intended to put THIS on their web page.
How is it done? The funny-looking codes at the end of the URL spell out the subversive message. You can use an obfuscator to create these codes.
Lesson for library webmasters: scripts that accept input from URLs or forms (even hidden forms) must not blindly use that input. Check your input before using it!
Even More
ZDNet reports on an even bigger flaw in IE, as shown here. Other tricks explained.
Wanker
Just for those who don’t know the term, Wanker is British slang for masturbor.
Re:Wanker
I’m guessing that the person responsible for the prank is a fan of the cartoons of Tom Tomorrow. See more of Tom’s This Modern World at the official site.