People have been customizing cars almost since the car was invented, but these days that often means playing with the software that controls many vehicle systems. That's not something automakers want people to do, though, and for the past few months they've lobbied to make it illegal.

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The 1998 Digital Millenium Copyright Act (DMCA) protects copyrighted materials like movies from being pirated, but automakers argued that their own software should be protected by the law as well. Effectively arguing that consumers don't own the software in their vehicles, they claimed modern cars have gotten too complex for shade-tree mechanics to tinker with. But the Feds didn't see things that way, and recently exempted automotive software from the DMCA.

Every three years, the U.S. Copyright Office considers potential exemptions that allow fair use of copyrighted materials. The automotive software issue was one of about two dozen proposed this year, and was granted by the office. That means owners can access software for vehicle repairs and modification without fear of prosecution. It also potentially means that research like the study that uncovered Volkswagen's emissions cheating can continue.

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There are some restrictions, though. The exemption does not include software related to a vehicle's telematics or entertainment systems, and it does not allow third parties that might engage in diagnosis, repair, or modification on behalf of the owner. That would require new legislation from Congress, officials said.

Speaking of Congress, there is already a bill being drafted that would make accessing automotive software illegal. Introduced in the House of Representatives, it includes language saying it "shall be unlawful for any person to access, without authorization, an electronic control unit or critical system of a motor vehicle."

If that bill doesn't pass, though, the DMCA exemption granted by the Copyright Office means owners will remain free to modify software as well as hardware. Of course, they'll still be responsible for any modifications that void a car's warranty, or run afoul of safety or emissions rules.


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