It's self explanatory.
Basically I've seen some hints of pretty blatant spoiler threads already starting to appear, thanks to the leaks. And you can bet this is only going to get worse with the trolls likely to make threads with topic titles that overtly spoil key parts of the game.
You can bet this is only going to get much much worse tomorrow once the reviews/streams embargo is lifted and then of course when the game is out.
I suppose the most surefire way to save yourself is to avoid internet access until you've played the game