Actually VHS tapes had Macrovision which was a 'kind of DRM'. It was a system that distorts the timing pulse at the start of each line. TVs ignore this section of video when playing. But video recorders used it to record. So that it was very, very hard to copy the video. Indeed the Macrovision people even managed to get JVC to fiddle with the VHS standard so it worked even better at protection. Trouble as always, if you happened to have a TV that was sensitive to Macrovision, your rented or bought movie waved and spluttered in shades of brightness! Back then you could order a replacement which had no Macrovision on it by contacting the movie distributor. IIRC Alien was the 1st VHS commercial film to use it in the Eighties and of course Star Wars: A New Hope. Both costed around £70 each....! Various TV broadcasters use it (to this day) to prevent the copying of their programmes by video recorders. IIRC Betamax and V2000 ignored the Macrovision protection. Various public electronic magazines had projects that you could build that bypassed it. In time, these became widely available as assembled units.