Possible Duplicate:
Add markdown support for hidden-until-you-click text (aka spoilers)
Let's be honest. There's nothing worse than checking your news feed and accidentally finding out the result of your favorite TV show or sporting event that you've PVR'ed/recorded. Checking my Facebook has become second nature... most of the time I forget to think whether or not there could be posts that I don't want to see/discuss yet!
The spoiler alert option allows people that have seen the show/movie/sporting event to still discuss it, while keeping the lazy/busy bums like me safe from spoiling an outcome. (Also could have a "disable" function for people who don't want to use it at all.)
It could be like: (click the little spoiler alert button)
Spoiler alert subject: Dexter Season Finale
"Holy crap! I can't believe Dexter killed that dude!"
And would show up on all news feeds as
"Dexter's season finale spoiler" Or "Spoiler alert: Dexter's season finale"
And just click the "reveal" button or something.