A friend posted a suicide alert as a joke on Facebook a couple weeks ago and two days later the police came knocking. They ended up keeping him in hospital for two days "just in case". The only reason he was there was that someone doesn't get his humor and reported it even though most people knew he was fine.
edit: I guess it is worth noting that the misinterpreted public post and resulting hospital time was worse than whatever minor crisis than he was dealing with at the time. Fortunately no major medical bills (Canada) but he definitely lost a few contracts.
