Privacy

Last updated: June 3, 2026.

Publisher. tkal is published by THansAI Research Group LLC. References below to "we", "us", or "tkal" mean THansAI Research Group LLC. The data controller for the purposes of GDPR is THansAI Research Group LLC. Registered agent: 2108 N St, Ste N, Sacramento, CA 95816.

Plain English version, because legal boilerplate is mostly useless to readers who actually want to know what's going on.

What we collect

If you subscribe by email: your email address, the timestamp of when you subscribed, and whatever Substack (the email platform tkal uses) records about your engagement — opens, clicks, bounces. That's it. We don't ask for your name, phone, IP-as-identity, employer, or anything else. If Substack asks for more during the signup flow, that's optional and you can leave it blank.

If you visit the site: Cloudflare Web Analytics counts page views in aggregate. No cookies are set for analytics. No individual tracking. We see "how many people read Issue №005 this week" — we do not see "Tony Yu in San Francisco read Issue №005 on Tuesday at 4:12pm." Cloudflare's analytics is privacy-by-design specifically for this reason.

If you ever buy a paid tier or a quarterly PDF: Stripe handles payment. Stripe sees the card and billing info; tkal never does. We see your email and what you bought. That's the minimum needed to deliver what you paid for and to keep records for tax purposes.

What we never collect: location data, device fingerprints, advertising IDs, social-graph data, cross-site tracking, browsing history, or anything similarly invasive. There are no third-party ad pixels on this site.

How we use it

Your email: to send you tkal. That's it. We don't sell, rent, or share email lists with anyone. We don't enrich your record from third-party data brokers.

Aggregate analytics: to know what's worth writing about, which pieces resonate, and whether the publication is growing. Nothing tied to you personally.

Payment data: to process the transaction, deliver what you bought, and comply with tax and accounting obligations.

Who else sees it

Three vendors:

• Substack — the email platform. Holds your email address and engagement data. Their privacy policy lives at substack.com/privacy.
• Cloudflare — hosts the site and runs the privacy-by-design web analytics. Their privacy policy lives at cloudflare.com/privacypolicy.
• Stripe — payment processing (only if you buy something). Their privacy policy lives at stripe.com/privacy.

Nobody else. Not data brokers, not ad networks, not "marketing partners." If that ever changes, this policy gets updated and the change is announced.

Your rights

Whether you live in California (CCPA), the EU (GDPR), or anywhere else, you can:

• §Unsubscribe — every email has an unsubscribe link. Click it and you're out. No "are you sure" gauntlet.
• §Request a copy of the data we hold on you. Email tony-yu@live.com, we'll respond within 30 days.
• §Request deletion of your data. Same email, same response window. We'll delete from Substack and from any local records.
• §Object to processing or restrict use. Email and we'll discuss.

Paid-tier and PDF records may have to be kept for tax and accounting purposes for the legally required retention period (typically 7 years in the US). We'll delete email, analytics, and engagement data on request; financial records we'll delete when the retention period expires.

Cookies

tkal itself does not set tracking cookies. Cloudflare may set a security cookie (a single anti-bot cookie that doesn't identify you). Stripe sets cookies only on its own payment pages, not on tkal. If you embed or share a tkal page elsewhere, the third-party site's cookies apply, not ours.

Children

tkal is not directed at children. We do not knowingly collect data from anyone under 16. If you believe we have collected data from a child under 16, email us and we'll delete it.

Changes to this policy

If this policy changes in a way that affects how your data is used, the change will be announced at the top of the next tkal issue and the updated date above will reflect it. No silent updates.

Contact

Privacy questions, data requests, or anything else related to this policy: tony-yu@live.com.