I was curious about the Shawn Hornbeck case after you mentioned it, and did some reading. It sounds like early on in the kidnapping, the kidnapper took him out to the country in his car and was about to kill him. Shawn begged him not to, promised never to try to escape and to do whatever the kidnapper wanted as long as he kept him alive. The kidnapper agreed, but said that he'd kill him if he ever disobeyed. So my guess would be that Shawn never trusted that, if he told somebody, they'd both believe him immediately *and* be able to protect him from the kidnapper (who was seriously about to kill him, so he knew the kidnapper could/would do it in a heartbeat), and probably after a while he got used to obeying and didn't really go through the process of thinking, hey, this is a time when I could safely tell them the truth and be rescued before he could get to me.