Well, there's a reason that DVD case, and often, the DVD itself says right on it, "Licensed for Private Performance Only".
"Public Performance" - whether at a commercial (for pay) venue, or not, is covered separately under Copyright Law (since like, the 70s or earlier, this was not something new with the DMCA), and must be licensed. Whether that means paying a licensing fee for that particular performance, to the appropriate rights-holder (or their broker), or purchasing a monthly license from an organization that handles things (music, for example, is handled via ASCAP, I don't know the name of the one that handles AudioVisual Performances (movies)), well, basically, you have to pay for it one way or another. Simply buying the DVD isn't enough, unless you are watching it "privately", which generally means at your home, or on your PC.