Wikipedians get rid of copyright violations from Wikipedia not only to avoid legal issues for Wikipedia, but also to ensure that their work is easier to re-use:

However, material copied from sources that are not public domain or compatibly licensed without the permission of the copyright holder (unless brief quotation used in accordance with non-free content policy and guideline) is likely to be a copyright violation. Even inserting text copied with some changes can be a copyright violation if there's substantial linguistic similarity in creative language or structure (this can also raise problems of plagiarism). Such a situation should be treated seriously, as copyright violations not only harm Wikipedia's redistributability, but also create legal issues. [emphasis added]

By contrast, Stack Exchange only removes copyright violations if the copyright owner complains. For example, moderators who have received flags from ordinary users that content is a copyright violation won't act on such flags:

This also means flagging content for copyright violations is pointless. As moderators, we can't make the decision to remove content or not on behalf of the copyright owner. Again, IANAL, but if I understand it correctly if they start doing that they could lose DMCA section 230 "safe harbors", because at this point we're making our own determination about what is infringing rather than being a "dumb" service provider; that could leave us liable for content that we miss. [emphasis in original]

Does SE sites containing copyright violations make it harder for third parties to re-use SE's data?

  • 4
    SE is a collaboratively edited website, just like Wikipedia is. If someone sees copyrighted content, and they have edit rights, they are free to remove it, just like Wikipedia. If the dispute continues, SE corporate may receive a takedown notice. Just like Wikipedia. I'm not sure I understand the distinction you're making.
    – user102937
    Commented Nov 30, 2011 at 23:00
  • I'm not seeing where Stack Exchange is different from Wikipedia: are you suggesting Wikipedia does something different from how SE handles content? Can you elaborate on how exactly (like the actual process) Wikipedia makes their content more easily reusable?
    – user149432
    Commented Nov 30, 2011 at 23:29
  • 1
    @MarkTrapp: In the answer I linked to in the question, it was stated that an ordinary user flagging content as a copyright violation will be (and must be) ignored. Commented Dec 1, 2011 at 2:18
  • Community members have neither the authority, nor the ability, to respond to DMCA take-down notices. Only SE corporate can do that. Also, flagging a post as a copyright violation doesn't meet the requirements for a DMCA take-down notice. Community members can, however, soft-delete content (which is still viewable by users with 10K reputation and above) that is not in the best interests of the community.
    – user102937
    Commented Dec 1, 2011 at 4:29

2 Answers 2


Community users can, and do, routinely removed plagiarized/copy pasted content from SE sites. If you see something that's clearly been lifted from another site, and it is verifiable (i.e. you can go to the website and verify that copying took place), you can redact it on that basis.

For material that cannot be immediately verified as copypasta, a DMCA takedown notice directed at SE Corporate is the appropriate maneuver.

If, by removal, you mean the purging of historical (edit history) content from the databases that run the SE sites, it is true that you need a takedown notice for that, because this action requires an SE developer (moderators do not have the ability to change edit histories). But this is also true of Wikipedia. Wikipedia keeps an edit history in much the same way we do, and so retains infringing material unless someone with higher than normal-user authority intervenes.

In practice, ordinary (soft) deletion of a post makes the content invisible to all but a vanishingly small percentage of the public (users with more than 10K reputation).

  • 1
    Should Joel Coehoorn's answer which states "flagging content for copyright violations is pointless" be modified if it's incorrect? Commented Dec 1, 2011 at 2:16
  • If you are making a copyright claim, you need to file a DMCA takedown notice with SE. But if you just want offending material edited out or deleted, you can do that yourself.
    – user102937
    Commented Dec 1, 2011 at 2:22
  • Do you think Joel's answer is accurate, and that I'm misreading it? Commented Dec 1, 2011 at 2:26
  • Joel says that you need to file a DMCA take-down notice if you want to make a copyright claim. He is correct. I'm not a lawyer, but there may be some legal basis; defending your copyright in this manner improves your standing if you have to subsequently defend your copyright in a court.
    – user102937
    Commented Dec 1, 2011 at 2:27
  • As a community user, I can remove infringing material if I see it. But I am not a representative of Stack Exchange; I cannot accept a DMCA take-down notice, because I have no legal authority. Does that make sense?
    – user102937
    Commented Dec 1, 2011 at 2:53
  • It makes sense. I don't think we're agreeing on what Joel's post is saying, though. Commented Dec 1, 2011 at 3:12
  • 1
    I went back and read Joel's post in detail, and it seems to me that he and I are saying exactly the same thing. What you seem to be missing is that anyone with editing/deletion rights can edit or delete any content at any time for any reason, assuming there is community consensus. That a DMCA notice is required for a "take-down" is beside the point; the community does not wait for a DMCA notice to remove offending content, nor does it have legal standing to respond to such notices.
    – user102937
    Commented Dec 1, 2011 at 15:44
  • 3
    If that sounds confusing, consider this hypothetical scenario: A copyright holder posts a comment stating that a post is in violation of the DMCA and requests that it be removed immediately. The appropriate response is: "DMCA takedown requests should be directed at SE Corporate." In the meantime, if the content is verifiably copied from another source, the community can still delete it, on the basis that it is inappropriate material for the site.
    – user102937
    Commented Dec 1, 2011 at 15:53
  • @Robert - I would add "Individual mods do not have the power to completely purge material from the database." to the response, so that the copyright holder can see a reason in the response and doesn't feel like he's been given the runaround. Commented Dec 2, 2011 at 18:11

Remember that Stack Overflow and Wikipedia are different, in that StackOverflow grants a higher degree of identity/ownership/authorship to the authors of content it hosts than does Wikipedia. That both helps and hurts Stack Overflow in terms of allowing re-use. It hurts (at least for promoting re-use), in that Stack Overflow has more stringent attribution requirements (this isn't necessarily a bad thing overall, though). It helps, in that violations are now (because of the prior condition) at least attributed directly to the correct party. If infringing content is re-used correctly, there is a name attached to it that says, in a nutshell, "This person promised us he has rights to the content, and gave us permission to redistribute it. If you have a problem, take it up with him."

Now moving on with regards to the copyright issue from my previous post raised here. It's important to remember from here on out that I am not a lawyer, and I have no legal training or experience. I'm just some guy that's followed this topic quite a lot.

I think you can make a good case that "diamond mods" are granted authority by SE Inc to act in certain specific situations on direct behalf (as agents) of SE Inc. It's worth noting here that the ability to respond to DMCA requests is explicitly excluded from what mods are empowered to do, as they cannot purge the material from the database. My belief is also that to best qualify for DMCA protection as a service provider, SE Inc and it's agents have certain obligations that they not distinguish between valid and invalid content (where "valid" means valid relative to the matters covered by the DMCA). Doing so could make it complicit in (and therefore potentially liable for) the content that exists on it's site.

This liability is not covered directly (and should be excluded) by the law, but actual case law and precedent is a funny thing. My interpretation is that, to guarantee the Section 230 safe harbors, the safest course is to play dumb entirely with regards to copyright.

To understand why, first consider the opposite: that SE Inc is allowed to choose when content may be infringing. Imagine that SE Inc notices a lot of MSDN material showing up on Stack Overflow, and starts policing the site for direct copying of Microsoft's MSDN material. However, they neglect to do so for Oracle's Java/OracleDB/MySQL documentation. There's a wedge there that Oracle, if it chose to do so, could potentially use in a legal fight to create liability for Stack Overflow with regards to infringement of Oracle copyrights, because in choosing to enforce one set of copyrights but not another SE Inc is itself making a statement — an act of speech with regards to Oracle's copyrights. I think neither Mircosoft nor Oracle would want to do this, and that Stack Overflow would likely respond to this imaginary scenario by beginning to police content for both. Stack Overflow would also likely win a contest, but Oracle probably has enough to make a long and expensive fight of it. The real problem is that there's no legal difference between Oracle and any small blog out there that may have content infringed. You would ultimately have to extend this policy to monitoring everything that came in to the site for any potential violation. This, to my view, is not what is intended by Section 230.

How, then, should a diamond mod respond to a flag for copyright violation? If the flag is directly from the copyright owner they would be unequipped to respond adequately. If it's not the copyright owner, it's not the mod's place to make a decision on the copyright owner's behalf — the mod doesn't know if permission was granted on a separate channel before posting, or if the copyright owner would prefer the infringing content remain online (for example in the simple interest of helping spread the information it contains). Moreover, the mod has no way of knowing whether or not the copyright owner is behind the flag.

Diamond mods should remember, then, that they are an agent of Stack Overflow, but not an agent of copyright holders. But there is something they can do, because there is a separate plagiarism issue: they can make sure the content is attributed properly, by use of a simple edit. This is something anyone with sufficient reputation can do, which is why I say that flagging copyright violations is pointless; most of the time, the correct moderator action is something you could do for yourself: edit to include good attribution. In a nutshell, the terms of use specify that you only post content legally, SE Inc has it's users' promise of that, and this should be good enough until shown otherwise.

This analysis isn't perfect. Some larger sites (ie: YouTube) already have policies and practices that implement preemptive filtering, so obviously it can be done. But I think Stack Overflow is in a different place than is YouTube: YouTube has much more contact with much more litigious copyright holders, and tailored their strategy appropriately.

Moving beyond copyright, any user (including mods) can choose to take a much harder line for plagiarized content, and respond through downvotes, comments, and/or edit deletions — but at this point it's important to remember that, while related, plagiarism and copyright infringement are not the same thing.

The trick is that Stack Overflow blurs the line between infringement and plagiarism because of the authorship issue from my first paragraph: the only way to see plagiarism without corresponding copyright infringement is if the copyright owner were complicit in the plagiarism. On the other hand, it is still easy (though attribution) to have infringement without plagiarism.

Update: tl;dr version:

The Stack Overflow terms of use specify that you only post content legally, SE Inc has it's users' promise of that, and this should be good enough until shown otherwise. Finding the original content elsewhere is not enough to "show otherwise". It proves a copy, but not whether that copy infringes, because we're not in a position to know if the copyright holder might prefer the post be left alone, had made an offline agreement with the poster to allow the post, or any number of other possible exceptions — innocent until proven guilty and all that. There is also a chance that making this choice would open a legal loophole to create some liability for Stack Overflow directly, though while possible I think it's less likely. What we can and should do is respond to the plagiarism issue by at least editing the post to include proper attribution.

  • So should SO moderators just take the position that they're not in the business of making decisions on copypasta issues (i.e. redaction), beyond providing a link to the copied material?
    – user102937
    Commented Dec 2, 2011 at 17:14
  • @Robert - that's how I see it. Commented Dec 2, 2011 at 17:36
  • Expanding, though, I don't think copyright ties our hands with regards to other issues. If we wanted to have a strict plagiarism policy a la academia that resulted in instant expulsion (ban) and failure (rep score set at 1), that could still be done separately, and posts flags for copyright could still result in a mod applying such a penalty. (not that I recommend this policy - it's just an example). Commented Dec 2, 2011 at 17:51

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