Lesson Content

The default posture: semi-public.

When you type something into Gemini, treat it the same way you would treat writing it on a whiteboard in a conference room – visible to others, retained in some form, and potentially reviewed. This is not a reason to avoid Gemini; it is a reason to be intentional about what you share.

Most professional and personal tasks can be handled without sharing anything sensitive. When sensitive context seems necessary, there is almost always a way to anonymize it without losing the value.

The six categories to keep out of Gemini.

Category 1 – Personal identification information. Never paste: Social Security numbers, passport numbers, driver's license numbers, government ID numbers, date of birth combined with other identifiers, or any combination of information that identifies a specific individual.

Category 2 – Financial account details. Never paste: Bank account numbers, credit card numbers, investment account details, routing numbers, or passwords or PINs for any financial system. Describing your financial situation in general terms ("I have significant savings but a variable income") is appropriate; pasting account numbers is not.

Category 3 – Passwords, credentials, and access tokens. Never paste: Any password, login credential, API key, security token, or system access code into a Gemini prompt. There is no legitimate use case that requires pasting a password into an AI assistant.

Category 4 – Protected health information. Never paste: Medical records, prescription details, therapy notes, insurance claim details, or any health information that identifies a specific individual. Describing a general health situation in anonymized terms for research or learning purposes is appropriate; pasting actual medical records is not.

Category 5 – Confidential business and organizational information. This category requires judgment. Be careful about pasting: proprietary product designs or trade secrets, unreleased financial results, strategic plans that are not public, confidential personnel matters, legally privileged communications, or client data that is not yours to share. Before pasting any work document, ask: would I be comfortable if my manager, legal team, or client could see this in an AI system?

Category 6 – Other people's private information without their knowledge. Pasting someone else's personal information – their email correspondence, their salary, their performance review, their health details – into an AI system without their knowledge raises ethical and potentially legal issues. Consider whether the person would consent if asked.

The anonymization technique.

Most sensitive topics can be worked with using anonymization – replacing specific identifying details with generic placeholders:

Instead of: "My client, [Name] at [Company], signed a contract on [date] for $450,000…" Use: "A client in the [industry] sector signed a contract for approximately $X in [quarter]…"

Instead of: "My employee [Name]'s performance review shows they missed [metric] by 40%…" Use: "An employee missed a key performance metric by 40%…"

The analytical task – helping you think through a client situation, draft a performance conversation, or analyze a decision – does not require Gemini to know the identifying details. Anonymize first, then engage Gemini.