What not to paste
The postcard rule: if you wouldn't write it on a postcard, don't paste it in a chat.
The lesson
Privacy in one lesson: what happens to chat data (one honest paragraph per major app), and the never-paste list — SSNs, account numbers, passwords, medical records, other people's secrets, employer confidential information.
The picture to keep
The postcard rule, illustrated: context about the situation ✓ · identifying and confidential details ✗.
Try it — 60 seconds
Before your next paste, do the 3-second scan: names I should remove? numbers that identify anyone? someone else's private info? Redact, then paste.
Copy it into ChatGPT, Claude, or Gemini — whichever you already use. Fill in the brackets with your real life.
Watch out
"Delete chat" doesn't necessarily mean deleted from training or logs. Assume anything pasted is out of your hands — because it is.