I am working on a small face-related dataset that will be publicly available for open research. I have looked into many copyright-free image sources like https://pikwizard.com/ and https://www.pexels.com/
pexels is kind of clear about their policies. https://www.pexels.com/license/
What is allowed?
All photos and videos on Pexels are free to use.
Attribution is not required. Giving credit to the photographer or Pexels is not necessary but always appreciated.
You can modify the photos and videos from Pexels. Be creative and edit them as you like.
What is not allowed?
Identifiable people may not appear in a bad light or in a way that is offensive.
Don't sell unaltered copies of a photo or video, e.g. as a poster, print or on a physical product without modifying it first.
Don't imply endorsement of your product by people or brands on the imagery.
Don't redistribute or sell the photos and videos on other stock photo or wallpaper platforms.
From these statements, it seems there won't be any copyright issues or violations if I simply use the face images for research without any major alteration.
It seems pikwizard claims to be "Royalty-free and safe for commercial use, with no attribution required". But their policy page is pretty complicated.
Is it possible to use images from pexels, pikwizard, and other similar websites to make a public, open-source dataset without any legal issues?
This part is confusing. I see there are face datasets from platforms like youtube (which I guess has a stricter license), but still, there are datasets like: cs.tau.ac.il/~wolf/ytfaces/index.html#overview I wonder if someone uploads the image which he/she doesn't own (breaking the copyright law in the first place), and I mention the source of the image on the dataset, am I still liable to break the copyright law? How these platforms are saved then in that case? Anyone can sue youtube, pexels, pikwizard for hosting their images, right? In short, is there a source I can use for public data?