Evidence of Copying
The easiest way for a copyright owner to prove a violation of her copyright is to obtain a copy of the protected work, particularly from the medium the infringer used to transmit or display it. For example, when a photographer encounters a copy of one of his photographs published without permission in a magazine, the magazine with the photograph in it proves the magazine violated the copyright. Similarly, if a songwriter discovers that a recording artist has recorded a song he wrote without first obtaining permission, the songwriter could use the sound recording of the infringing performance to prove the singer violated his copyright.
Proving violation of a copyrighted digital file, such as software code or digital music, can be more difficult to prove than the violation of a copyrighted photograph in a magazine. An infringer who copies a protected digital file commits a separate violation of the copyright every time a computer makes a copy of the file. Digital copies can add up fast. If the infringer uses a laptop to copy a protected file from a DVD to the hard drive, and the computer's CPU makes a temporary copy of the file in the laptop's random access memory during the process, the infringer has committed two copyright violations: one for the temporary copy of the file the CPU stored in his laptop's memory and a second for the copy of the file that was stored on the laptop's hard drive.
The U.S. Constitution delegates responsibility for intellectual property rights to the federal government. Copyright cases are tried in federal courts. Federal law provides a way for a copyright holder to obtain records of the alleged infringement. A process known as electronic discovery, or "eDiscovery," enables the copyright holder to inspect the alleged infringer's computers to determine whether there is evidence of a violation. The eDiscovery process may help the copyright owner prove a copyright violation.
A copyright holder can also prove copyright infringement by proving that both the infringer had access to the protected work and the infringing work is substantially similar to the original work. This method of proving infringement often arises in the context of two songs that sound similar to each other. For example, the alleged copyright owner may have submitted a recording of an original song to a famous musician who subsequently claims to have written a song that is substantially similar to the one the copyright holder submitted. The copyright holder may be able to prove infringement by demonstrating that the musician had access to a recording of his song and the musician's song is substantially similar.