Is copy-pasting code from Stack Overflow an infringement to CC BY-SA 3.0 or is it considered fair use?

Question

Actually CC BY-SA 3.0 is a license which looks pretty good for most Stack Exchange Network sites, but on Stack Overflow which is used mainly for coding questions, is pretty much rigid since a lot of answers contains portions of code that usually are intended to be copy-pasted.

For example yesterday I did need to copy the following 2 lines of code from How to make a div's background color translucent? in order to give some style to a css file.

background-color: #fff;
background-color: rgba(255,255,255,0.5);

As I understood the conditions on the Terms of service I should include something like the following in my code:

/*!
 * Code snippet from StackExchange Network question on <https://stackoverflow.com/q/4729196> by at. <https://stackoverflow.com/users/326389>
 * Edited by user <https://stackoverflow.com/users/3075942>
 * Answered and copied from <https://stackoverflow.com/a/4729214> by David Thomas <https://stackoverflow.com/users/82548/david-thomas>
 * Licensed under CC BY-SA 3.0 <http://creativecommons.org/licenses/by-sa/3.0/>
 */

Which could be ok to certain point considering just 1 copy-paste on my entire project. But not for the daily work.

As today, I needed to copy 20 characters from How would you convert secs to HH:MM:SS format in SQLite?, and I don't know if it's wrong to not attribute, but I know it's wrong to attribute 20 characters.

Is copying 1 or 2 lines of code considered fair use? Varies by country? Should we think on other license for programming sites?

Answer 1

Those 2 lines are public domain because they don't meet the threshold of originality. Copying them is not fair use: it's entirely free as far as copyright goes. This is valid in all countries.

However it's possible even for a single line of code to be original and hence copyrighted. The distinction is usually hard to make and varies per jurisdiction, which is why some users release their code snippets in the public domain with the Creative Commons Zero (CC-0) waiver, as recommended by FSF. See also a fuller list and users mentioning a license. Dual licensing is not forbidden by ToS, either.

I think most code snippets which are really meant to be copied "virally", or more or less indiscriminately, tend to be of the unoriginal, public domain kind.

I'm not sure you really need such a big code comment, that's probably another question.

Answer 2

For code posted on Stack Overflow, there are three relevant cases:

• {1} The posted code isn’t licensed under CC BY-SA 3.0. This could happen if the poster had no right to post/license it, or if the poster quoted it.

• {2} The posted code is not eligible for copyright protection (e.g., not meeting the threshold of originality, or being in the public domain).

• {3} The posted code is licensed under CC BY-SA 3.0.

If you want to include the posted code in your code (which you intend to distribute), you are

• {1} not allowed to do it
• {2} allowed to do it without restrictions
• {3} allowed to do it if you follow the terms of CC BY-SA 3.0

Note that {3} does not only mean that you have to attribute accordingly, you also have to license your code under CC BY-SA 3.0 (or under a compatible license in addition, in case you adapted the code).

---

Category {1} will hopefully be flagged (if the poster had no right) or formatted with quote markup (assuming the specific quote is legally allowed). But it’s your risk.

It’s not always easy to decide if code would fall into category {2} (it’s for judges to decide, should it come to that), but the two lines of CSS are most likely in category {2}, because there is no originality involved, anyone would do it like that. But if you are unsure, better be safe than sorry, and assume {3}.

Answer 3

I'm not a lawyer, and I don't actually know what I'm talking about here. So this is not meant as a legal answer, but asa different interpretation of this issue and my personal opinion on how to handle this.

Imagine the answer was simply describing the rgba() function and how it works. You would end up at the same code, but you wouldn't have copied it directly. Nobody could actually tell that you copied the code from the answer as it is simply the obvious method to achieve this goal in CSS.

I don't consider code that simply shows how to use a library or language feature to be an original work. The actual text of an explanation would be an original work. But if the code is simply demonstrating how to use a particular API or language feature, I don't think copying it needs attribution.

I think your example is pretty clear as there is simply no way for you to read the answer, understand the concepts and then arrive at an independent implementation of the concept. You will end up with pretty much the same CSS as it is posted in the answer, there aren't many different ways of implementing this.

Answer 4

No. There is no difference in copying one line or an entire code block from an answer. The license the content is licensed on requires you to attribute the copied content to a specific user, linking to his/her profile.

I understand this is quite difficult when it comes to copying only one line of code, but actually there is no difference. Another licence won't really help much.

Personally I don't mind if you copy some or all the code I posted. Usually when I want to copy some code from SO, I try not to copy it, but take the general idea behind it and rewrite the code myself, also based on the documentation I find from official sources.

(Small note: the license doesn't only protect the author, but also Stack Overflow Inc. from site scrapers)