The teaser trailer for the sequel to last fall's cleverly marketed mock-nonfiction smash hit Paranormal Activity is now online. And it's probably a smart thing to play up the whole "you demanded it" angle (even though Paramount's platform and shifting-city release plans were already largely predetermined), reminding audiences of the viral elements that helped in large part make the movie "theirs." We'll see if there's another shadow left in this book of shared skittishness, though.