Data obtained from the Stack Exchange API is cc-wiki licensed.

This license explicitly encourages the user of the API to copy, redistribute, remix and transform the data obtained from the API for any purpose, provided that appropriate credit is given and that the cc-wiki license remains.

If data obtained via the API was used to build a new website that displays tens of thousands of unaltered questions and answers reformatted for easier browsing, and if one of those questions contains a link to a copyrighted image, then would the user of the API be liable for displaying that image link on the new website?

To be clear, the data obtained from the API contains just a link to an image hosted on stack.imgur.com. The image was uploaded there by a Stack Overflow user who did not have a license to do so. That user is clearly liable; I'm asking whether the user of the API is liable. The data that they obtained via the API may contain hundreds of thousands of image links, any of which may violate copyright, and this places a burden on them to verify all image links for potential copyright violations before sharing and remixing the data.

In light of the top answer below, I've discovered a way to make easy money. Behold!

Copyright Infringing Poem

If the following poem is republished anywhere other than on law.stackexchange.com then I will demand $1000 in damages.

The Sausage
by Jason Hutchens

Oh mighty sausage, how juicy and sweet
The delicious smell of your sizzling meat
  • 1
    @tripleee Assuming that kranzky is the copyright holder for the poem, the license is quite clear and is still CC BY-SA 4.0. The combination of the Terms of Service and CC BY-SA licenses are quite clear that the CC BY-SA license is granted by posting and the license doesn't permit adding additional terms such as what is stated here. The copyright holder could add an additional complete license, which readers would then be able to choose to use instead of CC BY-SA, but the OP can't add terms to the CC BY-SA license, for multiple reasons.
    – Makyen
    Nov 24, 2023 at 6:35
  • 5
    @kranzky Not really, given that poem is copyrighted to you, you have full rights to license that as CC BY-SA 4.0. When you posted it here you did publish it under that license, so people could republish it as long as they meet the requirements for CC BY-SA 4.0. Your statement there does not even look like a license to me, it is just a statement that you "will demand $1000 in damages" You could replace that with something like "will eat cake" and you can see how that does not put anyone (except you?) under any legal obligation. Nov 24, 2023 at 11:47
  • 1
    @AbdulAzizBarkat right, because the poem is copyrighted to me and because I posted it then it was re-licensed so that users of the API can re-publish it without fear of me pursuing them for damages, but if I posted a poem copyrighted to somebody else without their consent then a user of the API that re-published that poem would be liable for copyright infringement, and the author of that poem could pursue a claim against them?
    – kranzky
    Nov 24, 2023 at 15:41
  • 2
    @kranzky Unless you can realistically argue that you could sell a license to that poem at $1000, I don't think you can just claim that as damages. (I also think you were too hasty to accept an answer; it's conventional to wait at least 48 hours. This is not a trivial topic.)
    – wizzwizz4
    Nov 24, 2023 at 18:56
  • 2
    @wizzwizz4 what I could do is send a letter to the person who republished the poem asking them for $1000 in compensation and advising them to consult a lawyer, knowing that they may just pay me instead, which is precisely what PicRights did to me, asking for $970 because I republished data from the stack exchange api that included an image URL to an unlicensed image. hiring a lawyer to defend my right to republish will cost me more than the compensation they are demanding.
    – kranzky
    Nov 25, 2023 at 4:06

2 Answers 2


Yes, he's liable.

A Partial Copy of a Fair Use is not necessarily Fair Use

Content that is used with Fair Use on Stack Exchange isn't necessarily used with Fair Use in the website that uses the data from SE. If, for example, someone discusses a poem, that is Fair use. But ripping the poem to another page and ditching the discussion no longer discusses the poem and thus is no longer covered under Fair Use.

You can't license what you don't own.

If someone includes a work that they have no rights to use in their answer or question, that does not transfer any rights into Creative Commons. In fact, you can't put a license on anything that you don't have rights to. Copying any content that someone else published as a copyright infringer doesn't make it ok - you just become a copyright infringer too!

  • 2
    Lower case then. You can't license what you down't own. Both infringe.
    – Trish
    Nov 23, 2023 at 14:27
  • 8
    "Copying any content that someone else published as a copyright infringer does make it ok..." I take it you mean "... doesn't make it ok." Nov 23, 2023 at 16:26
  • 3
    @kranzky It's not specific to CC licensed data. It's anything licensed under any license. As the person exercising the license, you're responsible for verifying that the person purporting to give you the license has the right to do so. There is, potentially, more risk when not getting the license directly from the person claiming they hold the copyright, but the risk exists there too. For licenses which re-grant a license to anyone who receives a copy, then there is risk that someone in the chain from the copyright holder lost the license and/or never actually was able to grant a license.
    – Makyen
    Nov 23, 2023 at 16:53
  • 7
    This analysis appears incomplete. It does not appear to take into account laws such as the DMCA, which, under specific conditions, provide a safe harbor for a service provider, which the entity described in the question could arguably be considered, and assuming that an agent for receiving DMCA takedown notices was appropriately designated as described in 17 USC § 512(c)(2).
    – Makyen
    Nov 23, 2023 at 17:19
  • 3
    Stack Exchange is, obviously, the original service provider. It's unclear to me that the the entity described in the question wouldn't be considered a "service provider", under the definition used in the DMCA. The definition for "service provider" in the DMCA doesn't require that the service provider be the original service provider. Of note is that due to the CC BY-SA license, the user does have an explicit contractual relationship with the entity mentioned in the question (i.e., the license). I don't feel that it can be said without some precedent, that they are not a service provider.
    – Makyen
    Nov 23, 2023 at 21:51

Not necessarily.

The Copyright, Designs and Patents Act 1988 has:—

  1. The copyright in a work is infringed by a person who, without the licence of the copyright owner,
    (a) possesses in the course of a business,
    (b) sells or lets for hire, or offers or exposes for sale or hire,
    (c) in the course of a business exhibits in public or distributes, or
    (d) distributes otherwise than in the course of a business to such an extent as to affect prejudicially the owner of the copyright,
    an article which is, and which he knows or has reason to believe is, an infringing copy of the work.

Subsection (d) would appear to apply to the circumstances described ("Copyright is infringed by distributing an infringing copy"), which means that if there is no reason to believe it is an infringing copy, that is an available defence.

That defence will probably only be rarely available, though.

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