I've got a number of software projects, licensed under varying licenses. For simplicity, let's take one of them, licensed under the GPL.

Obviously, the GPL requires various things, and there may be occasions where people don't do all those things. If I notice those, I see two choices:

  • Contact the relevant person with notification and request to comply;
  • Turn a blind eye.

Fine, that's up to me. However, if someone else contacts me to say that they've found someone who's not complying with the GPL, does anything change? Does their involvement and thus the fact that I am proven to know about the license violation change how I can react? Am I, in this scenario, obliged to enforce my license by contacting the offending party?

2 Answers 2



The GPL license doesn't have any specific requirements to make you enforce the license and the copyright holder is the only person who can take any action.

The copyright holder is the one who is legally authorized to take action to enforce the license.

(Violations of the GNU Licenses - GNU.ORG)

Copyright Law

So only something in base copyright law could cause you to lose your rights from non-enforcement. Short answer: No, you won't lose your copyright if you do not defend it. That is something that applies to a trademark.

In the United States, if a trademark owner stops using a mark without intending to resume using it in the future, the mark will be deemed abandoned. Under U.S. trademark law, non-use of a trademark for three consecutive years creates a rebuttable presumption of abandonment of the mark (whether or not it is registered). Temporary or seasonal non-use of a trademark, particularly when such cyclical use is typical in an industry or market, generally does not constitute grounds for abandonment under U.S. law. Rather, periods of non-use must be accompanied by the “intent not to resume use.”

In many other countries, grounds for abandonment depend solely on whether the mark at issue has been in use, without regard to the trademark owner’s intent. The period of non-use required to show abandonment of a mark typically ranges from three years (e.g., in Australia, Japan, South Korea, Canada, China, Russia and many Latin American countries) to five years (e.g., in various European countries, such as Ireland and Norway).

(Fact Sheet: Protecting a Trademark - International Trademark Association).

Laches defense

Another reason you may be unable to defend your IP rights after a long period of not enforcing it is what is called a laches defense. This is when there has been an unreasonable amount of time in pursing a claim. Laches is an affirmative defense and must be brought forth and proven by the defendant. The US Supreme court has stated that laches does not bar copyright infringement claims (Petrella vs MGM).

The majority rejected those arguments, however, saying copyright law was clear in allowing lawsuits up to three years after an infringing act, setting up a rolling period for owners like Petrella to sue although they can only collect on profits earned during that three-year window.

There is “nothing untoward” about waiting to see if an infringer’s investment paid off, Ginsburg wrote. In fact, the law “allows a copyright owner to defer suit until she can estimate whether litigation is worth the candle.”

The Supreme Court’s decision “brings certainty to this issue, which was unique in the Ninth Circuit,” said William Kane

(Unusual Split As Supreme Court Upholds `Raging Bull' Suit Vs. MGM - Forbes)

So there isn't anything different with someone telling you that someone has infringed on your copyright. You aren't required to enforce it. You can probably even wait and decide later that you want to enforce it but you can only do that within three years of the last infringing act and you can only expect damages based upon the last three years.

More useful info about copyright myths (including this): http://www.templetons.com/brad/copymyths.html

I Am Not A Lawyer... if you want real legal advice you should contact one.


No. You are not. You hold the copyright, you make up your own mind.

The legal concept of adverse possession does not apply to copyright, and so you can't lose your rights by failing to enforce them, either.

  • 3
    I heard that if you fail to enforce for one party then you can't enforce them for another. At least the courts won't agree with you then. Jul 18, 2015 at 22:13
  • How about a citation or a link to that?
    – bmargulies
    Jul 18, 2015 at 22:52
  • 7
    @ratchetfreak: IIRC this is a principle of trademark law but not of copyright law. An undefended trademark ceases to be a trademark, an undefended copyright does not. In any case I suppose you could, instead of "turning a blind eye", give the person you want to ignore a 12 month license to use/distribute the software under different terms. Repeat annually assuming you haven't changed your mind. Jul 19, 2015 at 0:22
  • 1
    @MikeD Making a derivative work without permission is infringement. I have read the Wikipedia link; you have misread it, by misunderstanding what "protected by copyright" means (it means "this has a copyright and you can sue people who violate that", not "you have the right to make this").
    – cpast
    Jul 19, 2015 at 18:40
  • 1
    @bmargulies That's because that's how they made the GPL; it's not something coming out of copyright law. The GPL legally could prevent making derivatives without redistribution, it would just violate the four freedoms.
    – cpast
    Jul 19, 2015 at 20:22

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