At this point I'm just assuming everything I ever create and post to the internet is going to be stolen. People have been stealing, reposting, and adding their own pay links to my art for years now, without the help of AI.
I've made D&D themed stickers that are now all over "free clipart" sites, despite me filing requests to have them removed. I've seen my graphics ripped off and included in someone else's art without credit. I've had people tell me that an ACAB image I made showed up as a sticker getting put up around Seattle. Facebook meme pages crop my username out of my posts all the goddamn time. Voice actors on YouTube use my posts for "dramatic reading" videos constantly, and only one has ever asked me permission or given me any cut of the profits from their video.
I see my art out in the wild with no source back to me, and I'm a tiny creator compared to a lot of others. People repost shit constantly, whether it's here, Pinterest, Facebook, Twitter, TikTok, YouTube, whatever. I remember the old tumblr days of "We Heart It is not a goddamn source" PSAs.
I think people are right to be concerned about AI, but at this point I'm much more concerned about it from the perspective of "companies want to use it to cut labor costs," and less "it's theft."
People didn't need AI to steal my art before now. I'm more concerned about trying to freelance in a market full of "oh, we can just get ChatGPT to write and illustrate our articles."