Pasting real material is the best way to get useful output — but real material carries real data: names, salaries, API keys, customer emails, unreleased plans. Once sent, you should assume it's outside your control. Many workplaces have policies about exactly this, and 'the AI needed context' is not a defense your security team will enjoy.
The good news: models don't need real identifiers to do great work. Structure matters; identities usually don't. Swap names for roles (ACME_CORP, CLIENT_A, my manager), keep amounts approximate when exact ones aren't the point, and never paste secrets — keys, passwords, tokens — under any circumstances.