'Bully' is a documentary which follows the lives of five kids and families over the course of a school year and tackles the devastating effects bullying has on teens and tweens. However the film has been given an 'R' rating by the Motion Picture Association of America, which will limit its access to the very kids producers hope to help.

Katy Butler, a Michigan teenager from Greenhills High School near Ann Arbor hopes to change that rating. Butler endured severe bullying during her middle school years when she came out as a lesbian.

She's started this online petition, urging the MPAA to change the movie's rating to 'PG-13.' The movement has already gathered over 155,000 online signatures.

Bullying affects nearly 13 million kids in the US each year. The film is set to open March 30th. Watch the trailer, and tell us what you think.