I've been wondering about this legal question for some time now. There are special artwork out there that is kept secret on fan-exclusive websites like Patreon, Fanbox, Fantia, etc. The artwork cannot be shared out in public and can only be retained for personal use unless you get permission from the artist themselves to be able to post otherwise.
What if the exclusive artwork is old and some sites that don't answer takedowns have been displayed on particular websites? It is a thing on the internet that if an artwork is posted on the internet where it can be searched with a simple search engine and the artwork has no watermark or indication of the artist, it is now considered open-sourced and anyone can use it as their profile or reference photos for commercial use without any restrictions or copyright violations.
There is some artwork that has been displayed on other sites, but not on E621. Is it okay if any user on this site can post an old rare artwork to the site with/without permission of the artist? Users who post this old artwork can edit the tags so that it is made in a certain to prevent confusion.

pmfieryflakes said:
It is a thing on the internet that if an artwork is posted on the internet where it can be searched with a simple search engine and the artwork has no watermark or indication of the artist, it is now considered open-sourced and anyone can use it as their profile or reference photos for commercial use without any restrictions or copyright violations.

Absolutely not. If permission isn't given, it's assumed all rights are reserved to the rights holder. If you find a random image on the internet without a watermark or any indication from the creator, it is still copyrighted to the creator by default.

watsit said:
Absolutely not. If permission isn't given, it's assumed all rights are reserved to the rights holder. If you find a random image on the internet without a watermark or any indication from the creator, it is still copyrighted to the creator by default.

The artist will still have the copyright and IP of the image. But because the artwork has no watermark or signature to the actual artist, it is assumed that the image is free for the public to use. Anything that you post in public media can be used by anyone. Either for personalization, gallery archiving, reference, or entertainment purposes.
But for the case of exclusive art from membership exclusive sites. I honestly think it's a complicated case. If a person manages to upload a private exclusive image/video to public media, the former artist will have the right to take down the post where the image resides. However, if the artwork hasn't been taken down for a long time and more copies of it have been published on other parts of internet media. Will the artist still have the right to take it down? Or there will be no way that copyright laws will protect the image and it will now be considered free to use under the artist's ownership?

pmfieryflakes said:
But because the artwork has no watermark or signature to the actual artist, it is assumed that the image is free for the public to use.

This assumption is incorrect.

pmfieryflakes said:
The artist will still have the copyright and IP of the image.

That includes control over copying and redistribution. So being that they have copyright of the image, it is up to them if you're allowed to copy and use it publicly, regardless of where you found it and regardless of any signature the image may or may not have.

pmfieryflakes said:
But because the artwork has no watermark or signature to the actual artist, it is assumed that the image is free for the public to use.

No. Without any grant given by the artist, all rights to allow copying and distribution of the image are left to the artist. It is not free for public use if the artist hasn't made it so.

pmfieryflakes said:
However, if the artwork hasn't been taken down for a long time and more copies of it have been published on other parts of internet media. Will the artist still have the right to take it down?

Yes. For individuals in the US, copyright lasts for the life of the author plus 70 years (absolutely ridiculous, but that is what it is). As long as they haven't given a license with the image (where the terms of that license would then apply), they have the right to take it down at any point in their life. And even after they die, whoever the rights transfer to (next of kin, their family/estate, etc) inherits all those same rights.

Either from the US, the Uk, Japan, or any other country in the world. Copyright and IP laws are different in certain places I believe. Copyright laws for my place barely or do not protect the person's IP on the internet without putting a watermark or receipt of ownership of the image. (Which is unfair for other forms of art in the past who don't have their names on before).
Now I am no lawyer. I obviously am incorrect with this and I shouldn't say this like I know everything. But I get influenced by other people stealing and using art that is voided from us, and yet people still use them like they weren't in trouble. Maybe I live in a place where copyright laws weren't fully implemented in the community and people with the internet can just use anything they find on their search engine. But it confuses me all the time. If the artist felt that their art was been wrongly used without their consent, they have the right to accuse the person of stealing their IP. Some or most people just don't seem to care because "They found it on a Google Image Search engine and was downloadable"
Third-party gallery websites unlike E621, Furrafinity, rule34, etc. have rules and guidelines that help protect the artist's IP and takedown unauthorized publishment of art. But I discover some sites that are open to the public and illegal post copyrighted IPs to the media.
Man I'm just confused. Real life laws are much more different than virtual laws.

pmfieryflakes said:
Either from the US, the Uk, Japan, or any other country in the world. Copyright and IP laws are different in certain places I believe. Copyright laws for my place barely or do not protect the person's IP on the internet without putting a watermark or receipt of ownership of the image. (Which is unfair for other forms of art in the past who don't have their names on before).
Now I am no lawyer. I obviously am incorrect with this and I shouldn't say this like I know everything. But I get influenced by other people stealing and using art that is voided from us, and yet people still use them like they weren't in trouble. Maybe I live in a place where copyright laws weren't fully implemented in the community and people with the internet can just use anything they find on their search engine. But it confuses me all the time. If the artist felt that their art was been wrongly used without their consent, they have the right to accuse the person of stealing their IP. Some or most people just don't seem to care because "They found it on a Google Image Search engine and was downloadable"
Third-party gallery websites unlike E621, Furrafinity, rule34, etc. have rules and guidelines that help protect the artist's IP and takedown unauthorized publishment of art. But I discover some sites that are open to the public and illegal post copyrighted IPs to the media.
Man I'm just confused. Real life laws are much more different than virtual laws.

I think you're mistaking some people not caring and flying under the radar for the law saying it's okay.