CC0 = Public Domain. Do whatever you like with it.
CC BY = Only attribution is required. You may create derivative works. As long as you attribute the creator of the work, you have complied with the license.
CC BY-SA = You must attribute the work to the author AND any derivative work must be licensed under identical terms in order to comply with the license.
Edit: I should add that it doesn’t hurt to tell people that you have used their Creative Commons licensed photos, as most folks do appreciate knowing that they’ve helped someone else, especially an educator or researcher.
I am not a lawyer, but note that the requirements are actually a bit more than just attributing the creator even for CC-BY, you need to do things like repeat any copyright notices, give a source URI, a reference to the license, indicate if changes were made and a few other things (some of these only “to the extent reasonably practicable”).
Most of the time failing to do these extra things probably won’t come back to haunt you since people who are CC-BY licensors usually want their stuff to be reused widely and the most recent license versions include a repair period where your permission (which terminates on breach) gets reinstated if you correct things within 30 days of being made aware of problems. However there are people (so-called “copyleft trolls”) who bank on people not understanding this, who make a lot of CC-licensed stock photography (often under older license versions without repair provisions and/or more exacting technical requirements) then send out manipulatively worded legal threats in bulk alleging technical defects in the attribution strings and demanding settlement money from reusers. This sort of bad-faith predatory behaviour will afaik get you banned from Wikimedia and Flickr but is regrettably legal so it makes it extra important to get it right.
Thanks for the reminder to finally get around to switching all my photos to CC-BY. I never quite figured out a good workflow for manually adding them to Wikimedia, nor do I really know which ones are likely to be needed, so hopefully someone will do something with some of them. :)
Yes, you are technically correct here. And I agree it’s an important note. The main gist — which is what I was offering — is that you “give appropriate credit” in accordance with the license. That’s the beauty of CC licenses: You don’t need to ask for permission.
Here’s what the Creative Commons folks say, exactly:
For CC BY, credit for their work and acknowledgement of the license; for the other licenses, only a few conditions on how the work may be reused.
That was an important issue, but the core issue should not be as widely applicable to media on iNaturalist. Part of the problem was that Flickr allows users to apply old versions of the license to current media. The CC 2.0 licenses include a harsher term for inadvertent violations, which was exploited as a business model, than the current 4.0 version:
As Doctorow explains, the primary issue of CC 2.0 licenses is that they include a clause that if a reuser violates the attribution agreement, even if it’s clearly by accident and not with malintent, the CC 2.0 license is terminated, thereby leaving the reuser open to legal threat.
Some Flickr users hope that reusers will incorrectly attribute CC 2.0 media, allowing the original creator to then target the reuser, sometimes with the threat of significant statutory damages. This goes against the guiding principle of Creative Commons.
Creative Commons addressed this with its CC 4.0 license, which guarantees users the same 30-day grace period that Flickr now requires.
Hello thanks for your response - I can only see random images which aren’t mine when I enter my iNat userid?? When I search with yours though I see lots of lovely images of insects etc. Maybe this means I have no images loaded?
And if you don’t want to have that license apply to all, but only some, you can change individual licenses manually from the “Edit” page of the respective observation.
