I publish a fishing site. One year I redirected my site to PETA. People were freaking out, thinking the site got hacked. A local TV station even did a story on it, thinking the site really was hacked. (They never even contacted me to check.)
Other years I came up with stories like the site being sold or me not having time to do it anymore. The board was closed down entirely for the day. People freaked and the emails poured in.
Yesterday I posted a bogus story about a new world record fish that many are seeking (largemouth bass). Not as over-the-top as other years, but it got a few people.