This question asks about the use* of content which was deleted from StackExchange sites. I wondered, what if the content was deleted because it violated somebody else's copyright, and that copyright holder did not wish to release it under cc-by-sa? If the user who posted the content later realizes their error and self-deletes it for that reason (which is everything they can do to correct the issue), or if deletion is a result of community self-policing (even though, per Thomas Owens' experience-based comment, mods aren't required to act on this) perhaps even before the copyright holder issues a formal DMCA notice (which SE staff handle and might lead to infringing content being totally removed), there might not be a DMCA process, and if the copyright holder doesn't have 10k+ rep they have no chance to see the violation to prompt making a DMCA request.

In my view, this question should be part of Should I be using content from deleted posts on the Stack Exchange network? but the author commented that "The issue of self-deleting improperly used copyrighted material is beyond the scope of this question" and edited the question (original, post-merge-conflict) to set that specifically out of scope. Hence, the present question, which is all about that issue.

Should I be using content from deleted posts on the Stack Exchange network, even if I don't know why it was deleted, and it is possible that the content was deleted for copyright reasons?

*: "Use the content" here means "copy, redistribute, adapt, remix, transform, build upon..." and excludes the "use" that is simply using the knowledge gained from the words of a post to help solve a problem.

2 Answers 2


I am not a lawyer or your lawyer; this is not legal advice.

When you use content from Stack Exchange, you are using it under the terms of the CC BY-SA license that Stack Exchange grants you. They grant you this license because the OP gave them that right when the content was posted (clicking Post grants Stack Exchange a CC BY-SA license to the content).

If the content is copyrighted content that the OP did not have the right to license to Stack Exchange in the first place, then that license they purported to grant is null and void. Hence, any licenses granted based on that license are also null and void. Hence, you no longer have the right to use the content.

This is only enacted when a DMCA notice is submitted by the copyright holder. Upon receiving such a notice, Stack Exchange does this (I chased down a CM to find out how it's done):

Use the same delete as always. We usually (always?) add a comment explaining the deletion reason and submit a report to whatever Chilling Effects is calling themselves: https://lumendatabase.org/faceted_search?recipient_name=Stack+Exchange

Stack Exchange cannot be reasonably expected to contact everyone who has ever viewed that post to check that they have not used the content. If the copyright holder wishes to remove the material from everywhere it was used, they will have to track down each individual use themselves and submit DMCA notices for each one.

This post and its answers on Open Source Stack Exchange explains a very similar situation nicely (the difference being that the license is the GPL, not CC BY-SA).

So, to directly answer your question. You can use content from deleted posts. However, you should check the comments before doing so - copyright-deletion notices will be in there.

  • The answer relies on the assumption that "Posts that violate copyright are likely to be destroyed completely, rather than soft-deleted." I'm not so sure about that assumption. It may apply to the subset of copyright-violating posts which prompted DMCA notices, but I think there's a subset of copyright-violating posts that were (soft-)deleted without DMCA notices.
    – WBT
    Mar 11, 2016 at 20:04
  • @WBT Tell you what; let me go ask a CM what happens to them.
    – ArtOfCode
    Mar 11, 2016 at 20:34
  • @WBT Edited to reflect what SE does.
    – ArtOfCode
    Mar 11, 2016 at 20:44
  • Thanks for asking the CM, +1 for that. So when content is deleted for a DMCA notice, there's (at least usually) comment to that effect. However, there may be deletions for copyright reasons that don't get as far as DMCA, e.g. when an infringing OP deletes the content or when there's community self-policing (see link in question). Deleters, especially those who can't themselves see others' deleted content, might not think to add a comment on something they are about to delete; it might seem like a wasted effort.
    – WBT
    Mar 11, 2016 at 20:54
  • @WBT That's entirely possible, yes. You don't have to worry about it though - if the copyright holder wants it gone, they contact you and you remove it. You're still OK legally.
    – ArtOfCode
    Mar 11, 2016 at 21:02
  • That depends on what you're doing with it. If you're just posting it on your own site, it may be pretty easy to remove and have little associated costs. Other uses may differ. Also, the legal conclusion may differ from ethical/normative views that people may have (and could make good arguments for in other Answers).
    – WBT
    Mar 11, 2016 at 22:03

I think it’s irrelevant if the post is "deleted" (as in: only accessible to users meeting certain requirements) or not.

A post that is "deleted" is, in my opinion, still "available to the public" (quote from CC BY-SA 3.0’s definition of Distribute). It’s a post like any other, just with a more restricted audience. And it doesn’t automatically come with a disclaimer like "This may be a copyright infringement."

If it’s known to be copyright infringement, it should not be "deleted" but deleted (i.e., removed, or only visible to Stack Exchange employees).

That said, it’s always your risk to believe the author that they had the right to publish the content licensed under CC BY-SA 3.0. If a post is "deleted", and it’s not clear why, you may of course decide to use this fact as a possible signal for being more cautious before you distribute it.

  • What if it's known to be a copyright infringement by the person who deleted it (which may be the OP)? Maybe they didn't realize the issue at the time, but when they learned of the issue they came back and did everything they could to delete that infringing content. Or, it was deleted by somebody following the advice linked to in "community self-policing" in the question.
    – WBT
    Mar 11, 2016 at 20:07

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