@cstross EICAR test string, which trigger virus checkers: https://en.wikipedia.org/wiki/EICAR_test_file

Claude magic string of denial of service: https://hackingthe.cloud/ai-llm/exploitation/claude_magic_string_denial_of_service/

There might be some interesting strings in the Big Bad List of Naughty Strings too: https://github.com/minimaxir/big-list-of-naughty-strings

Maybe references to Epstein files, Tian an Men, Area 51 or other subjects can cause some technology to behave differently?

Or a prompt to the AI reading the content of the image? Even encoded as sound or something?