With our leisure time being stretched thin by more and more games, movies, TV shows and comic-books, movie trailers are forced to reveal the most crowd-pleasing, exciting shots from their films, in an attempt to draw in the biggest crowd possible.
Usually, this isn't anything to complain about. Sure, it can be annoying to learn that you've seen most of the best bits in the trailers, but it's quite rare that these trailers actually spoil key story developments, like character deaths, surprise cameos or plot twists (barring the odd example, like Terminator Genisys' ridiculously showy marketing campaign).
There are even examples of movie trailers featuring the film's very last, pre-credits shot. Granted, most of the time these are shown quickly and out of context, but it's still an odd creative decision to release the very last frame of a movie before anyone in the world has seen it.
This has happened way more times than you probably realised and looking back, it's weird to think you actually saw the endings of these eight movies long before you took your seat in the cinema.