A number of films slated to debut at the Sundance Film Festival in Utah next month are making the rounds within the industry via bootlegged copies. Michael Cera‘s documentary comedy "Paper Heart" and the Kevin Spacey drama "Shrink" are just some of the films "being traded faster than tapes at a Grateful Dead concert," sellers tell The Hollywood Reporter. The finished-film market may be spurring distributors to check out films to determine how to use their more limited resources, but John Sloss, head of Cinetic Media, tells the trade the illegal copies "could virtually kill the market for a movie. From our perspective, this is war, and you’re at your peril if you don’t treat it that way." Sellers argue that because the films aren’t finished, buyers get an inaccurate picture of a movie designed to be seen in an audience with other buyers.