How do I prevent the misuse of my applications and/or their source codes?

Maybe something along these lines:

You are NOT allowed to bundle this application with anything that may count as: Malware, Adware, Spyware or an otherwise undesirable application.

Also, the way I see it I cannot just say 'illegal uses are forbidden' in the license since laws differ from country to country and applications are used in different places around the world.

Any solutions?

  • 1
    Also, would this make it non-free?
    – undo
    Feb 8 '16 at 16:09
  • 4
    It would make it non-free. Feb 8 '16 at 16:13
  • 1
    The legally interesting question is, when your Open Source software is bundled or otherwise combined with an illegal application (i.e. in violation of some national law), do you as the copyright owner have legal standing for a civil suit ? You may not have banned the practice by license, and in fact have made an explicit choice to allow "Evil" usage, but it such a ban necessary ?
    – MSalters
    Feb 9 '16 at 9:12
  • To people bent to do to evil, violating the licence is just gravy
    – vonbrand
    Feb 10 '16 at 13:57
  • Doesn't Apple have some licence with something in the lines of "This soft- and hardware may not be used to create nuclear weapons" ?
    – Charlie
    Feb 13 '16 at 13:39

I completely understand where you are coming from here. No one wants to hear that some of the code they've written has been used to make the leading virus of all time. Sadly, a licence with such a provision couldn't be called open source. This is actually addressed by the Open Source Initiative themselves:

Can I stop "evil people" from using my program?

No. The Open Source Definition specifies that Open Source licenses may not discriminate against persons or groups. Giving everyone freedom means giving evil people freedom, too. Fortunately, there are other laws that constrain the behavior of evil people.

Licences have tried to stop any "evil" acts, but chances are, if someone is using your software for evil, you probably won't know about it anyway. Furthermore, how would you define evil? By creating a definition, that could be unique from licence to licence, you could actually end up discriminating from groups that may not use it for "evil."

Basically, such a licence would not be considered open source. I wouldn't worry about it - people wouldn't respect such a licence if they were to use it evilly, so such a clause likely wouldn't stop anything. These people clearly have no moral or ethical sanity.


The JSON license is what you are looking for. It has the appearance of a general permissive open license with one additional line in it:

The Software shall be used for Good, not Evil.

This has caused numerous problems. It has made it so that it needs a special license grant for various Three Letter Companies (cough IBM cough). You can read about it at IBM and its minions … in which they author gave a grant that IBM can't really be sure that their users aren't doing evil, but they'd really like to distribute JSON.

Of course. So I wrote back – this happened literally two weeks ago – “I give permission for IBM, its customers, partners, and minions, to use JSLint for evil.”

There are also class that it was removed from Google Code back in the day because it wasn't a free license.

Similar works now are more simply licensed and suggestedto be used for good.

JShrink is licensed under the BSD License. See the LICENSE file for details.

In the spirit of open source, use of this library for evil is discouraged but not prohibited.


Lets look at that open source thing.

As described at The Open Source Definition

5. No Discrimination Against Persons or Groups

The license must not discriminate against any person or group of persons.

6. No Discrimination Against Fields of Endeavor

The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.

Thus, no. You can't say "evil people can't use this" and you can't say "you can't use it for evil" if you are using an open source license. It doesn't matter what it is or if you agree with it or not - you cannot restrict the software's usage if the software is to be licensed under an open source license.


The goal of a good contract or license to be 100% clear, with a bright line that both sides (and courts) are likely to agree is crossed or not.

A license that prohibits use in some vaguely-defined product category or usage scenario would be inviting a court battle over disagreement of what constitutes Malware (or whatever particular evil you are concerned with).

I suppose you could build a license that has 10 pages of legalese carefully defining Malware in an ironclad way, so there is no confusion, but nobody is ever going to agree to those license terms. In fact, even if they don't intend to produce malware, they won't bother spending the legal fees to have their counsel evaluate this long, one-of-a-kind license to determine whether they can safely adhere to it. So your software will be unused. Disuse is usually not a desired goal of open source software.

  • 2
    Not to forget it will be incompatible with all open source, thus mostly useless
    – vonbrand
    Feb 12 '16 at 23:16

Good Question! This is one of the biggest concern since the SourceForge fiasco. Like the other answers say, such provisions couldn't be made while sticking to the open source definition. However, there are some steps that you can take as the author of an open source project if such a scenario does happen:

  • Firstly, report the malware link to Google specifically detailing what the said malware authors have done and how they have used your FOSS to create a malware.
  • Secondly, cry out in the entire social media (FB, Twitter, Reddit, Hacker News, etc.) and tell the community that your FOSS code is being misused (Precedent to this is the GIMP project in the recent sourceforge fiasco). People will become alert and no one will download the said malware. Chances are that the malware author could be bundling other FOSS too like yours, so many others will also be benefited by your action.
  • Thirdly, perform some SEO to thwart the malware link on Google. If Google doesn't obey your request, you can use SEO as a tool to make sure that when people search for "Foo software" on Google, the homepage of your FOSS project called Foo should appear above all others.

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