There is a new tool that was just released that poisons images for AI called Nightshade. It causes the image to appear as something different to the AI. This can pollute an entire model to produce distorted images. Not a huge deal for a lora, but it would waste a lot of time on a checkpoint. The danger is that the poisoning can be merged in from other models.
https://venturebeat.com/ai/nightshade-the-free-tool-that-poisons-ai-models-is-now-available-for-artists-to-use/
I don't personally want to get into a discussion about who has what rights to do what. That is going to be a can of worms that will be solved in the courts and legislatures. I just wanted people aware that this is a thing now and to be aware of training image problems going forward.
The cover image was mentioned in the article. It is a cow.