Proving a Claim of Software Theft

Let’s say you think that someone has stolen your software code or other intellectual property. What can you do? These kind of disputes ordinarily involve copyright infringement--someone has violated your copyright in your intellectual property. When a copyright dispute arises, there are often several self-help steps a copyright owner can take. These generally amount to telling the infringer to stop the infringing activity and/or pay for the infringement. When push comes to shove, however, there is only one remedy with teeth in it: to ask a federal court to order the infringing activity halted and to award a judgment for damages.  

Because this type of litigation is procedurally complex, an attorney skilled in copyright litigation is required. However, before seeing a lawyer, you should determine whether you could have a valid claim for copyright infringement. Hare the major things you must establish to prove infringement:  

  • you are the lawful owner of all or part of a work protected by a valid copyright
  • one or more of the copyright rights you own has been infringed, and
  • the person, partnership or corporation being sued has actually done the infringing act or contributed to it (called a contributory infringer).

Ownership of a Work Protected by Copyright

The question of infringement does not even arise unless the work allegedly infringed is protected by copyright. This means that the work must be:

  • Fixed in a tangible medium of expression. A work is sufficiently fixed if it exists on paper, on disk, or even just in computer RAM.
  • Independently created. You cannot sue someone for copying software or other materials that you copied from others.
  • Minimally creative. The work you believe has been infringed upon must have been the product of a minimal amount of creativity. The vast majority of software easily satisfies this requirement; but some databases may not.

Read more about Protecting the Copyright for Your Software.

Infringement of Your Copyright Rights

As a practical matter, most cases of software copyright infringement involve a violation of the owner’s exclusive right to make copies. That is, someone copies all or part of somebody else’s program without the owner’s permission. For purposes of illustration, this discussion assumes that is the case here. Although the focus here is on the right to make copies, the principles discussed relative to copying also apply to all copyright rights that make up the entire bundle of rights (such as the exclusive right to display the work or create derivative works based on it).

To prevail in an infringement lawsuit, the plaintiff must prove that an infringement actually occurred. If someone is caught with an exact copy of a copyrighted work, or is seen copying it, the plaintiff has what is aptly called a smoking gun. The infringing villain has been caught red-handed.

Unfortunately, this type of evidence usually isn’t available. Most infringers are smart enough to attempt to disguise their copying. Moreover, there are rarely any witnesses to copyright infringement. Infringement usually happens behind closed doors and the participants rarely admit their involvement.

This means that in most cases you must prove two things to establish infringement:

  • that the claimed infringer had access to your work, and
  • that the infringing work is substantially similar to your work.

If these are proven, copying is inferred because there is no other reasonable explanation for the similarities.


To prove access, you must show that the alleged infringer had the opportunity to view and copy your software. This requirement is easy to show if the work is mass-marketed. It may be more difficult if the work has only been accessible to a very few people or the source code has been protected as a trade secret. Problems can develop, for example, when software that is very narrowly distributed under a license agreement is pirated.  

Substantial similarity

Proving substantial similarity is usually the crux of any copyright infringement case. Assuming the alleged infringer had access to your work, the similarities between your work and his must be compared to see if copying may reasonably be inferred. The similarities must be such that they can only be explained by copying, not by factors such as coincidence, independent creation or the existence of a prior common source for both programs.

The first step most courts take is to filter out the unprotectible elements of the plaintiff’s program before comparing it with the allegedly infringing program. Under this filtration test, those elements of the plaintiff’s program that are not protected by copyright are identified and eliminated from consideration. This includes, for example, ideas, elements dictated by efficiency or external factors or taken from the public domain. (After this filtration process is completed, there may or may not be any protected program elements left. If there are, this core of protected expression is compared with the allegedly infringing program of the defendant to see if there has been impermissible copying. (Computer Associates International, Inc. v. Altai, Inc. 982 F.2d 692 (2d Cir. 1992); Gates Rubber Co. v. Bando Ltd., 9 F.3d 823 (10th Cir. 1993).)

The defendants in most software copyright infringement actions will doubtless claim that any alleged similarities relate only to elements of the plaintiff’s program that should be filtered out as unprotectible. This filtration test can make it very difficult for plaintiffs to win infringement cases. Indeed, it makes it difficult for plaintiffs and their attorneys to know whether they have a good infringement case in the first place, since opinions can and will naturally differ as to what elements should and should not be filtered from the infringement analysis.

The clearest cases of copyright infringement involve wholesale copying of your computer code. You’ll likely have far more difficulty proving infringement when you allege that nonliteral elements of your program have been copied—that is, things other than computer code such as the user interface. The bottom line is that it is virtually impossible for even the most experienced software attorney to predict with confidence whether a nonliteral infringement claim will succeed. In effect, plaintiffs who bring these cases enter a crap shoot: You pay your money and take your chance.

Learn more about Patent, Copyright, and Trademarks.

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