Copyright infringement basics

FIRST STEP: Probative Copying

Question is whether actual copying took place. 

Ninth Circuit calls this “extrinsic similarity.”

This can be shown in two ways:

  1. Direct proof (by admission or other direct proof); OR

  2. Circumstantial evidence.  This, in turn, can be shown by access to the plaintiff’s work PLUS “substantial similarity” between the parties’ works:

    1. Access: remember that access without similarity is not copying.
    2. Similarity: often called “substantial similarity” but this is more of a probative similarity.  In other words, are the similarities between the works probative of copying by the defendant?
      • Expert testimony often needed.
      • In this step, the court will consider copying of both protected and unprotected material.
      • Where proof of access is missing, some courts will use “striking” similarity (a high level of similarity) as proof of access. Along similar lines, some courts (the Second Circuit) treat access and similarity on a reverse sliding scale. In other words, the more proof there is of similarity, the less of a need for proof of access. See the table below:

No similarity between works “Substantial similarity” plus proof of access “Striking similarity” without proof of access
Then no probative copying even if access is shown. Most likely there will be a jury issue on copying. May be a jury issue in the Second Circuit. However, the Seventh Circuit points out a need of some proof of access, or some proof that the defendant’s work wasn’t copied from another source such as the public domain.

SECOND: Improper appropriation

Question is whether there was copying of protected expression.

Often called “substantial similarity,” “misappropriation,” or “improper appropriation.” Ninth Circuit calls this “intrinsic similarity.”

  1. Approaches vary. Some courts will “subtract” non-protected material; others will look to “totality.” Analysis particularly difficult with works where the expression involves the arrangement of non-protected materials such as compilations and computer programs.

  2. Experts. Experts generally cannot be used here.

  3. Perspective. Use lay public, though some cases the fact-finder will look at a particularized audience.

  4. Level of similarity. Similarity here need not be striking.

  5. “Substantial similarity” versus “substantial simlarity.” Remember that courts often confusingly use the phrase “substantial similarity” to refer both to probative similarity and to misappropriation.