The program (Limewire/Frostwire/Gnutella clients in general) is not...repeat...IS NOT...selecting the files for you to download. You are selecting the files to download, or you have some sort of virus/spyware-type program which is connecting to websites which are pushing this content to you.

Run some anti-spyware and virus cleaning utilities (mebbe go search the forums here for some suggestions, or try versiontracker.com), stop trying to download movies from the internet (copy them from friend's DVDs if you must), and be careful before you hit the "download" button.