I wonder if Disney has learned from what happened with the Age of Ultron trailer, where they told everyone about it a week ahead of time and then someone leaked a low-quality bootleg of it the very next day.

Then again, that movie hasn't been shrouded in secrecy the way Episode 7 has. An audio recording from the comic-con footage in Hall H went up on YouTube and neither Disney nor Marvel seemed to care. The ep7 teaser, on the other hand, will be the first time anyone outside of the production sees footage from the film, and it's going to be ultra-teasery footage at that.