Not an artist but I've never heard of this software, it sounds like a good idea! If it's available for free download & use I may start using it to protect art that I commission

I asked my main artist to reupload my stuff and she gave me the green light. Idk if that helps but there's something. Still need to do it tho...

well you know it like placebo button (read on wikipedia) , it easy to bypass Nightshade simply by non-ai upscaling and applying some filters (anisotropic and bilateral) and color profile transformation and down scale to original or to common resolution for traning 512x512 or 1024x1024, batch conversion can be done using imagemagick via small bash script, i try it on some images that nightshade protect and in most cases bypass it .
For train ai to copy your art style need 25-40 images that easy to get from furaffinity archive(or other sites) that uploaded before tool was used, old art is not protected,