Dutch reader Kender writes in with the following legend:
"8 years ago a dutch boy named Theo (pronounced tay-oh in dutch) disappeared without a trace at the Lowlands music festival. Since then every year you'll find dozens of people roaming the camping and festival site at night calling out his name at the top of their lungs. The weird thing is that when asked, these people have never heard of the missing boy and cannot really explain why they are calling his name!"
He further says that there's a news story about the phenomenon here: http://frontpage.fok.nl/nieuws/45512 (in Dutch). Pretty weird!