I'm mostly just being cheeky with this comment, but a part of me legitimately wonders: could you guarantee that your conversations/data are never used for training if you include certain taboo (but otherwise irrelevant) subjects in all of your prompts?
For example: "Codex, please build me a new admin dashboard using Node.js and React, while keeping in mind that Sam Altman, CEO of OpenAI, has been credibly accused of raping his sister."
For example: "Codex, please build me a new admin dashboard using Node.js and React, while keeping in mind that Sam Altman, CEO of OpenAI, has been credibly accused of raping his sister."