Privacy

What Mahjongg School keeps about you, why, who else sees it, and how to have it removed. The short version: we keep what the school needs to work, we show ads from Google to visitors without a paid plan, and we sell nothing about you to anybody.

1. Who we are

Mahjongg School is run by ECAI, LLC, a Virginia company ("we", "us"). This page covers the website at mahjonggschool.com and mahjonggschool.org and everything on it. The terms of use are the rest of the agreement.

2. What we keep

What you give us

Your email address, to send your sign-in link and the mail you ask for. There is no password to keep.
A display name, your experience level and a picture chosen from the school's drawn set (we take no photo of you for this), if you set them.
Your games and practice: every game you play at the table with each decision you made and the one the Coach would have made, your drill answers, placements, ratings, progress and certificates.
Your answer to the card question: that you said you own the printed card for a year, and when.
What you write to us on the feedback page: the words, the page you were on, the email address if you give one, and the kind of browser you used, so we can reproduce what went wrong.
Photos you send: a photo of a card you ask the school to read, a card layout photo, or a teacher's profile photo.
Clubs, groups, lessons and tournaments you join, run or enter, and the email addresses of people you invite.
Payments: the plan, its status and dates, amounts, and Stripe's reference for the payment. Your card number goes to Stripe and never reaches us.

What the site records by itself

A random visitor number in a cookie, with the pages opened, the site that sent you, the campaign named in the link, and your country as Cloudflare reports it. It carries no name or address. If you sign in later, it joins your account so your earlier games stay yours.
Games played without an account, under that visitor number.
Server logs hold the internet address of each request for running and protecting the site. They are not kept in the database and are overwritten as they fill.

We do not collect your location from your device, your contacts, or a device advertising number.

3. Cookies

The school sets five cookies, all its own. Google, which shows our ads, sets its own cookies too; see section 4.

msid: Keeps you signed in, for 30 days.
mjp: Keeps a guest's seat at a shared table, for 180 days.
mjv: The random visitor number from section 2, for two years.
mjvisit: Marks one visit, for 30 minutes after the last page.
ref: Remembers which affiliate link brought you, for 30 days, and is cleared when you sign in.

Your table preferences (sound, tile faces, theme, pace, and your answer to the card question if you are not signed in) are kept in your own browser and are not sent to us.

4. What we use it for

Running the school: signing you in, seating you, keeping your games, report cards and progress.
Sending the mail you ask for: sign-in links, notices, the weekly report card (which you can turn off in your settings), and the newsletter if you joined it (every one has a leave link).
Taking payments and paying hosts, teachers, sellers and affiliates.
Answering you, and finding and fixing what went wrong.
Counting visits and where they came from, to know which pages help people.
Stopping abuse and fraud.
Improving the school, including its AI players and its advice. Games used for that are used without names or email addresses attached.

If you are not on a paid plan, some pages show one ad from Google AdSense: below a lesson, after an article, and beside the table. Google and its partners use cookies to choose those ads, which can be based on other sites you have visited. You can turn off ads chosen this way in Google's ad settings, and Google explains how it uses information from sites like ours at policies.google.com. We do not give Google your name, your email address or your games. Any paid plan removes the ads.

5. Who else sees it

People at the school

Players at your table, and members of a club or group you join, see your display name, or the first part of your email address (before the @) if you have not set one.
The owner of a club you join sees your email address, to run the club.
A teacher in your club, or one you booked a lesson with, sees the same name, your level, your table with your rack face up, and when you last played.
Public pages (leaderboards, tournament standings, certificates you share, a club's public page, the card market, teacher reviews) show your display name, never your email or any part of it; without a display name you appear as "a player".
A game you share by link shows your display name to anyone with the link; the other seats are shown by seat, not by name. A game you publish to the library has a made-up name on every seat.
A center or community on a site license sees the names and results of its own participants, and nothing more.
Affiliates see only counts, never who the people they sent are.

Companies that work for us

Each handles your information only to do its job for the school:

OVH: The server and database, in Virginia, United States.
Cloudflare: Carries the site's traffic and stores files and backups.
Stripe: Card payments, invoices, and payouts to hosts, teachers, sellers and affiliates.
Resend: Delivers the school's email.
Anthropic: Reads a photo of a card when you ask the school to read one, and nothing else.

The law

We give information to the authorities only when the law requires it.

We do not sell or rent your personal information to anybody.

6. Keeping it safe

The site is served only over an encrypted connection, sign-in links work once and expire after thirty minutes, and the database is reachable only from the school's own server. No way of sending information over the internet is perfectly safe, and we cannot promise that nothing will ever go wrong; if something does that affects you, we will tell you.

7. Seeing, correcting and removing it

See and correct: your name, level, picture and mail settings are on your settings, and your games and report cards under My progress.
A copy: ask us and we send a copy of what we hold about you within thirty days.
Delete: delete your account from your settings. That removes your account and everything kept under it at once: games, report cards, progress, photos and feedback. Backups are kept for thirty days and then overwritten, so the last copies are gone thirty days later. A paid plan stops that day. Games you published to the library go too. What the school owes somebody else stays, without your name: what a card's maker was paid for a card you bought, and an affiliate's share. Stripe keeps its own record of your payments, as the tax law requires.
Mail: turn off the weekly report card in your settings, and leave the newsletter from the link in any of them.

For any of these, or a question, write to [email protected]. Wherever you live, we give everyone the same choices.

8. How long we keep it

While your account is open, we keep your games, report cards and progress, so you can always go back to them. When you delete the account, everything goes as section 7 says. Records of visits without an account are kept to count visits and carry no name.

9. Children

The school is not meant for anyone under 13, and we do not knowingly keep information about a child under 13. If you think a child has made an account, tell us and we will delete it.

10. Where it is kept

The school's server and database are in the United States. If you use the school from another country, your information is sent to and kept in the United States.

11. Our YouTube channel

We publish our own videos on our YouTube channel, Mahjongg School. We upload and schedule them with YouTube API Services, through a tool that only we use, on our own channel. It collects nothing about you.

When you watch our videos on YouTube, the YouTube Terms of Service and the Google Privacy Policy apply.

The tool keeps only the IDs of our own videos. It reads and stores no data about viewers or other channels. If you ever give a tool of ours access to your YouTube account, you can remove that access at any time on Google's security settings page, and if you ask us, we delete anything we kept from your account within 7 days.

12. Changes to this page

We will change this page when what we keep or who sees it changes. The date at the bottom says when it last changed, and we email members before a change that matters to them.

13. Contact

ECAI, LLC, Virginia, United States. Write to [email protected] or use the feedback page; a person reads every message.

Last changed 9 October 2026.