What does AI actually know about you?

Happy Thursday!

Welcome back to HOW TO // AI. Last week an AI safety researcher said out loud that he puts the odds of AI killing every human on earth at better than one in ten. It went everywhere. Somebody probably forwarded it to you.

Here's what nobody forwarded you: while you were reading about that, your chatbot quietly wrote down your kid's name, what you earn, and the client contract you pasted in last Tuesday.

One of those risks is a coin flip a decade out. The other already happened. Today we're dealing with the one you can actually do something about — in ten minutes, this morning.

Here's what's in today's issue:

🎯 Grab today's free download first: The AI Privacy Audit (free Notion checklist) — every menu path for ChatGPT, Claude and Gemini on one page, so you can do this once and be done.

Let's get into it!

Most people picture a chatbot like a search box. You ask, it answers, it forgets. That stopped being true a while ago and nobody sent a memo.

There are three separate things your AI is holding right now, and they're worth telling apart:

That third one moved fast this year. In July, Google began using uploaded photos and Search materials to train its AI by default, opt-out available. In August, OpenAI shipped a feature that keeps a record of the apps and websites you visit. Meta claims the right to use your AI conversations to target ads across its apps.

So I opened mine up. Here's my Claude memory settings — read what it has stored, then look at the third toggle and the red line underneath it:

Can you believe it even knows my dog's name? Nobody sat me down and asked for that. It came up in passing and it wrote it down, the way a very attentive stranger would.

And then read the red line again: "Deletion didn't finish. Some memories of sensitive topics may still be saved."

I had turned sensitive topics off. It told me — honestly, and to its credit — that turning it off didn't fully work. That's a company being straight with me, and it's still a sentence that should make you sit up. Most tools don't tell you that at all.

Then I went and looked at Grok, which keeps something it calls a User Memory. Not my chats. A dossier:

It had my name, the username out of a config file on my machine, what laptop I use, which operating system, which virtual machines I'd tried and why I abandoned the first one — and the fact that a software license of mine expired in March. There were pages and pages of user memory. It knew more about me than I did, it felt like!

I never told it most of that in so many words. It assembled it, the way you'd assemble a picture of a stranger from a year of their small talk.

Want to see yours? Ask:

Fifteen seconds. You will not forget the answer.

Then I ran it in ChatGPT and I can’t show you the output. Here’s why…

My ChatGPT memory page was nearly empty. A few lines. Nothing I'd mind a stranger reading.

Then I ran the prompt. It came back with pages about me. Family, work, money, the things I've been chewing on for months.

I can’t show you much of that response and it’s PAGES long.

Here's what's going on, because it took me a minute to work out. ChatGPT has two memory systems, and only one of them has a list you can read:

An empty memory page tells you nothing about the second one. Mine was blank and it still knew everything.

So when you do the audit below, don't stop at the list. Find Reference chat history and decide, deliberately, whether you want it on.

And do it in this order: run the prompt first, then look at the settings. The other way round, you'll see a short list, decide you're fine, and close the tab.

Before the click-by-click, two numbers that explain why this matters more than it used to.

39.7% of all AI interactions involve sensitive data, and the average person feeds sensitive data into an AI tool once every three days. That's from a Cyberhaven report published in February. Most of it goes through personal accounts, not company ones — 32.3% for ChatGPT, 58.2% for Claude, 60.9% for Perplexity.

And in February, one AI chat app leaked 300 million messages belonging to 25 million users. Not a sophisticated hack — a misconfigured database left readable by anyone with the URL. The researcher who found it then scanned 200 other iOS apps and found 103 of them had the same hole.

Nobody's chats were safe because nobody's chats were secret. They were just unlooked-at.

Here's the fix. Ten minutes, once. Run the profile prompt first, in each one, before you touch a setting.

ChatGPT — Settings → Personalization → Memory. Two things live here and you want both. Manage memories opens the visible list — read it, delete anything you wouldn't hand a stranger. Reference chat history is the toggle with no list behind it; that's the one that knew everything about me. Turning off Reference saved memories switches chat history off too. Then Settings → Data Controls and turn off improving the model for everyone. (Not seeing any of this? You're probably in Codex or the sidebar app — go to chatgpt.com in a browser and click your name, bottom left.)

Claude — Settings → Memory. Three toggles: search past chats, generate memory from chats, include sensitive topics. Under them, your actual stored profile. Read it.

Gemini — myactivity.google.com → Gemini Apps Activity. Set auto-delete. While you're there, check what July's default training change picked up.

Then adopt one rule, which is worth more than all the toggles combined:

If you wouldn't put it in an email to a stranger, don't paste it into a chatbot on a personal account.

Client contracts, medical letters, anything with a social security number, anything under NDA. Use your company's approved account for company data. That one habit closes more risk than every setting on this page.

Every menu path above on one page — ChatGPT, Claude, Gemini and Copilot — plus the "what do you know about me" prompt, and a short what-never-to-paste list you can send to your team. Do it once, keep the page, hand it to somebody else. Free, as always.

→ Get the AI Privacy Audit

A lot of you joined in the last few weeks, so here's the short tour of the shelf:

Forward this to one coworker who's drowning in meetings - you're a third of the way to the first reward:

Your unique link and progress tracker are right here:

The prompt I run before every meeting
Thirty seconds before you walk in, and the hour goes differently. Plus the free Meeting Kit.

The 3 prompts I actually reuse
The editor, the extractor, and the explainer — long on purpose, plus the free Paste-In Prompt Pack.

Pass your AI cert. First try.
3,301 practice questions. 11 AI certs. An AI tutor. On your phone, free to start.

Have a question you want answered? What's the meeting on your calendar you'd delete forever if you could? Email [email protected] and you just might be featured in an upcoming issue!

This newsletter is your starter kit for mastering AI with confidence. We keep things simple, show real examples, and focus on quick wins you can repeat.

Stay curious, stick with it, and watch your skills grow week by week!

Until next time :)

-David

P.S. If your day job is enterprise IT - VMware, cloud, storage, infrastructure - I write a second newsletter that decodes that world in ten minutes a week: Subscribe to Enterprise Techie →

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