1) Regex filtering/sanitation. Have a nice day. 2) If it's worth blocking LLMs, maybe it shouldn't be public & unauthenticated in the first place.

Anyone who runs ads on their website has a financial incentive to publish content publicly while blocking LLM trainers

Many of these characters actually have genuine uses in non-English languages, so it would be hard to just blindly remove all of the characters from every prompt without breaking other things.