Privacy policy

Mahjong Tribes (mahjong.tsunagu.ch) is a small, non-commercial site run privately by Matthias Frey to help groups of friends organise mahjong games. For any question about your data, or to use any of the rights below, write to mahjong@tsunagu.ch.

• Your account: your name, email address and password. The password is stored only as a one-way hash; nobody can read it, including us.
• Your profile, if you fill it in: a photo, your city and country, your level, the mahjong styles you play, whether you play for money, and whether you want game emails.
• What you do on the site: the tribes you lead, join or ask to join; the sessions you start and your answers to them; the games you host or sign up for; the days you mark as free or able to host; and the venues you add, with any address and notes you type in.
• Sign-in and password links: when we email you a link, we keep a scrambled copy of it until it is used or expires (24 hours for sign-up, 1 hour for a password reset).
• Server logs: like any website, the web server records each request — your IP address, the time, the page and your browser type. We use these only to keep the site running and to deal with abuse, and delete them after 90 days.

We don't ask for your birthday, phone number or anything else. Don't put sensitive information in notes, descriptions or venue details.

Only to run the site for you and your tribes: to let you sign in, show your plans to the people you play with, match players by level and style, fill and waitlist tables, and send the emails you ask for. We don't sell or rent your data. There is no advertising, no tracking and no analytics. Your data isn't used to train AI models.

• Members of your tribes see your name, photo, city and country, level, styles and money preference, and what you do in that tribe (session answers, game sign-ups). They never see your email address.
• Other signed-in people see only what a tribe shows outsiders: a public tribe's name, leader, size, description and location, and when its games are, in which city. Hidden tribes don't appear at all.
• The days you mark as free are never shown with your name: your tribes see only how many members are free on each day.
• Venue addresses and notes are visible only to you and the tribes you share the venue with.
• The site administrator can see the member list, including email addresses, to run the site, send invitations and remove accounts.
• Nothing is visible to people who are not signed in, except the public help pages.

• Hosting: the site and its database run on a server we rent from Oracle Cloud in its Tokyo data centre (Japan).
• Email: emails are sent from mahjong@tsunagu.ch through FireStorm ISP in Switzerland. Your email provider will of course also handle the messages it receives.

These providers store or carry the data for us; they don't get to use it for their own purposes. If you live elsewhere, using the site means your data is kept in Japan and passes through Switzerland.

We email you when you sign up or reset your password. Emails about planned games are sent only if you turn them on in your profile, and each one has a link to stop them at once. We don't send newsletters or marketing.

The site sets only the cookies it needs to keep you signed in and to protect forms against forgery. There are no advertising, analytics or third-party cookies, and the fonts are served from our own server, so your browser doesn't contact anyone else. A profile photo is cropped in your browser before it is uploaded.

Your data is kept while you have an account. You can delete it yourself at the bottom of your profile, or ask us to. Your profile, photo, answers, sign-ups, free days, venues and the games and sessions you host go with it; a tribe you lead passes to the member you choose, or is deleted if you are its only member. Leaving a tribe removes your answers to its open sessions and your sign-ups for its upcoming games. Before updates to the site we take a backup copy of the database on the same server; these copies, and the server logs, are deleted after 90 days. So once your account is deleted, nothing of it remains after at most 90 days.

You can change your name, photo, location, level, styles and email setting at any time on your profile, and delete your account there. You can also ask us, at mahjong@tsunagu.ch, to:

• tell you what we store about you and give you a copy;
• correct something that is wrong;
• delete your account and everything linked to it;
• stop using your data for something, or object to how we use it.

We answer within 30 days. If you are not happy with our answer, you can complain to the data-protection authority where you live — for example the FDPIC in Switzerland, the Personal Information Protection Commission in Japan, or your national authority in the EU.

All traffic is encrypted (HTTPS), passwords and email links are stored only as hashes, and the database can't be reached from the internet. No system is perfectly safe; if something goes wrong that affects your data, we will tell you.

The site is meant for adults. Please don't sign up if you are under 16.

If we change this page, we will update the date at the top. If a change affects how your data is used, we will tell members by email before it applies.