I am sure most of you guys are into DVDs... but I am not there yet...
I always wondered how they protected VHS tapes from being copied...
I guess this is the answer:
Macrovision Anti-Copy Protection
WRS Motion Picture and Video Lab is a licensed
duplicator for Macrovision.
The Macrovision videocassette anticopy process is the most effective and widely used technology for preventing "back-to-back" copying of videos using two VCRs. The technology is applied to over 550 million videocassettes annually and is used by every MPAA movie studio on some or all of their videocassette releases. Over 220 commercial duplication facilities around the world are equipped to supply Macrovision videocassette copy protection to rights owners. In the U.S., over 1,500 corporate, educational, and special interest rights owners apply the copy protection process to their packaged media.
Macrovision copy protection is available through WRS.
How It Works
The technology consists of a carefully timed sequence of electronic pulses that are added to the video signal during duplication. These pulses are transparent on original cassette playback, but cause copies made on most consumer VCRs to be degraded to the extent they no longer have much entertainment value.
Specifically, when attempting to make a copy of a copy protected cassette, the Macrovision technology will confuse the recording VCR's automatic gain control (AGC) system. Illicit copies made on over 85% of consumer VCRs exhibit some or all of the following characteristics: dim and/or noisy pictures, loss of color, intermittent or permanent loss of video, picture tearing, etc.
The Copying Problem
Unauthorized copying is a major problem confronting video rights owners worldwide. A recent study found U.S. consumers admitted to having one unauthorized copy of a prerecorded videocassette for every six originals. The study found that over 30% of VCR households admit to having unauthorized copies, and that the total annual revenue loss due to copying is estimated at $370,000,000 annually. The study also found that the copying problem is not restricted to Hollywood blockbusters. Millions of households were found to have illicit copies of music, documentary, children's, sports, exercise, instructional, religious, and other non-theatrical programs.
Industry Support
In the U.S., usage of copy protection enjoys widespread industry support. The key association representing video retailers, the Video Software Dealers Association, has endorsed rights owner usage of copy protection on videocassettes, as well as other media. The National Association of Video Distributors has recommended copy protection be utilized on all cassettes. And a survey of the nation's top video specialty store chains found that 93 of the top 100 chains in the U.S. wanted all their cassettes copy protected, and the majority reported they would be inclined to increase their purchases of titles they knew were copy protected.
Now... anyway to "bypass" this thing ??
It sucks... a lot of times I rent a movie and I wish i could keep a copy...