Commerical Use License?

[micmarsh]

Hello There,

Thank you for this comprehensive list! I'm considering using it for a commercial web filtering service but have a couple of questions about the license:

1. How would we go about providing proper attribution as per the Creative Commons license? The public facing landing page, the terms of service, etc.?
2. Perhaps more fundamentally, how is the data in this repository available under CC or any single license given that the source repositories have many different licenses, including GPL and some with no license at all?

I'm not a lawyer so these (especially 2.) are just my layman's thoughts trying to put things together and make sure we have all our ducks in a row before getting a lawyer involved.

Thanks,
Michael

[CodeAlDente]

Hi @micmarsh,

thanks a lot for the thoughtful questions!

1. Attribution under CC BY-SA 4.0

The simplest way to provide attribution is exactly as shown in the repo:

[Bon-Appetit/porn-domains](https://github.com/Bon-Appetit/porn-domains) is licensed under [CC BY-SA 4.0](https://github.com/Bon-Appetit/porn-domains/blob/main/LICENSE).

Where you place this depends on your setup — many projects put it in their Terms of Service, documentation, or an “About / Credits” section that’s visible to users. The key is that the attribution is public and links back both to the repo and to the license.

2. Why this list is licensed under CC despite mixed sources

It’s true that the repo aggregates data from different upstream sources with different licensing situations, but what’s published here is not just a raw copy of those lists. While domain names on their own are just factual data, the act of curating, validating, and maintaining a consolidated dataset is a creative effort that can be licensed. I’m combining sources, running validation (syntax checks to remove invalid domains, DNS checks to confirm domains are still functional), and normalizing/removing certain prefixes so the resulting dataset is more consistent and applicable. The outcome of these processes is a derived database, which Creative Commons explicitly says can be licensed under CC BY-SA 4.0 (see their guidance on databases).

For transparency, I always list the original sources used, though not every source is included in every update — for example, if a source hasn’t changed, it may be skipped (see discussion #43).

[micmarsh]

Thank you @CodeAlDente! With reference to 2., it sounds like the ability to aggregate a database like this is built into Creative Commons itself, and depends on the definition of "substantial portion" of a database?

[CodeAlDente]

Important

Please note: This explanation is for informational purposes only and does not constitute legal advice; for questions about how this domain list can be used in a commercial environment, please consult a qualified lawyer.

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[...] it sounds like the ability to aggregate a database like this is built into Creative Commons itself [...]

Yes, that’s correct — Creative Commons 4.0 explicitly allows databases to be licensed under CC, and it also applies to the sui generis database rights that exist in some jurisdictions. As CC explains:

“Yes, CC licenses can be used to license databases. The most recent version (4.0) may be used to license databases subject to copyright and, where applicable, sui generis database rights.” ¹

Those rights restrict copying or reusing substantial portions of a database (including repeated extraction of smaller parts):

“Sui generis database rights prevent copying and reusing of substantial parts of a database (including frequent extraction of insubstantial parts).” ²

However unlike copyright, database rights protect the maker’s investment, not originality.

[...] depends on the definition of "substantial portion" [...]

There isn’t a strict universal definition of what counts as a “substantial portion”:

“There is no bright line test for what constitutes a ‘substantial portion’. The answer will depend on the law in the relevant jurisdiction. Note that what constitutes a substantial portion is determined both quantitatively and qualitatively. Also, using several insubstantial portions can add up to a substantial portion.” ³

Finally, regarding what is actually licensed under CC:

“When a CC license is applied to a database, the database structure is licensed (if copyrightable), and the contents are licensed (if copyrightable). Where sui generis database rights exist, those rights are licensed as well.” ⁴

The safe takeaway is that if someone is reusing or redistributing a meaningful chunk of the curated dataset from this repo, the CC BY-SA 4.0 license applies. Using trivial or isolated parts might not trigger obligations. But as soon as you’re drawing on the list in any real way, it’s best to treat it as covered by the license.

Footnotes

1. CC FAQ – Can I apply a Creative Commons license to databases? ↩

2. CC FAQ – What are sui generis database rights? ↩

3. CC FAQ – What constitutes a “substantial portion” of a database? ↩

4. CC Wiki – Data and databases under CC licenses ↩

[micmarsh]

Sorry about the delayed reply! My concern was less about how my organization would re-use this dataset directly and more about indirect liability we may have (and direct liability you could have) related to the definition of "substantial portion" for all of the source databases.
This is too far into the legal weeds for a layman's speculation to carry much weight, so I'll accept your first answer as satisfactory in order to tie up loose ends. Thank you again for all of your help!