Spoiler Alert! A Long Tradition of Ruining Movies

"I see dead people"

"Who is Keyser Soze?"

"Luke, I am your father"

Those are some of the greatest movie mysteries and some of the most maddening spoilers of all time.

Just a little while ago a friend posted a status update on Facebook, spoiling a movie that I hadn't seen. I was a little irked at first but then I got to thinking, what are the rules when it comes to spoilers? The movie came out over a year ago and it could be argued that if I really cared, I've had plenty of time to see the movie.

So what do you think the rules should be when it comes to spoiling movies? Is there a grace period where people should give the benefit of the doubt to others who may not have seen the movie yet and not say anything publicly?

Tell us about your favorite spoil-able movies and what you think the rules should be in the comments section below!