Public performance rights(PPR) or an umbrella license must be obtained prior to showing, unless showing meets several conditions of "educational" use. Some films already come with PPR.
"All other public performances of Videos are illegal unless they have been authorized by license. Even “performances in ‘semipublic’ places such as clubs, lodges, factories, summer camps and schools are ‘public performances’ subject to copyright control.” (Senate Reprt No. 94-473, page 60; House Report No. 94-1476, page 64)."
http://www.mplc.com/aboutLaw.php
Reading is a right. Censorship is not.