What we keep about you
In short: a random profile number and what you do in the feed. A name and a handle only if you set them yourself. An email only if you gave it and agreed to be contacted. No IP addresses. One button erases everything.
Profile
When you start scrolling the feed, the server creates a profile with a random number and puts the cookie mc_s, a session key, in your browser. The database keeps only its hash. Your browser keeps the theme, the language and marks not yet sent. There are no other cookies, no ads and no third-party counters.
What you do in the feed
Your “interesting / not interesting” marks, reactions, what you saw, opened and saved, “Guess” answers, “more / less / hide”, and the interests the feed learned from them. Why: to pick the next cards and to remember your choices on other devices. Only total counts per card are made public, never profiles.
Name, handle and bio
None until you set them. Your handle and name are visible to everyone on your page /en/u/<handle>/. Search engines are asked not to index it. Change or remove them in the “Profile” card.
Only if you gave it yourself and ticked your consent to be contacted; the date of the consent is kept too. A sign-in provider passes your email only if you ticked that before signing in. Erase the email any time in the “Profile” card. We send no ads.
Signing in
You can sign in with a passkey, or with Google, Apple, X or Telegram if those buttons are in the “Profile” card. For a passkey the server keeps its public part. For a provider, only the provider’s permanent number of your account: no name, photo or friends. While you sign in, for 10 minutes at most, the cookie mc_o is set.
IP address and browser
Not kept. To keep robots from flooding the feed, the server counts requests per address in memory for a few minutes and then forgets them. Site statistics are only “how many of what per day”: no profiles, addresses or browser strings.
How long
As long as the profile exists. An empty profile without a sign-in, marks or activity deletes itself after six months. A session lasts a year, then the server starts a new one. Every night the database is copied, encrypted, to Cloudflare R2 storage; the copies are kept for 35 days at most, so what you delete disappears from them too.
Notifications and digest
The bell in the feed shows who followed you, replies from the editors and what is new from people you follow; at most 200 notifications are kept, for 90 days at most. The rest only if you turned it on yourself in the “Profile” card. Push: your browser’s subscription address and the topics you chose. The email digest, once a week, only with the box ticked and the address confirmed; every email has one-click unsubscribe and no open tracking. The Telegram digest: the number of your chat with the bot, nothing else; /stop or the button in the profile turns it off.
How to erase it all
“Delete profile” in the “Profile” card erases everything at once: marks, history, name, handle, email, sign-in methods, notifications, push subscriptions, the digest and the link to the Telegram bot. You can also do it piece by piece: erase the email, unlink a sign-in method, “Sign out everywhere”.
Who else is involved
Cloudflare carries every request to the site, like any delivery network; it sees the IP address. OVH is the French host whose server runs the site and the database. Cloudflare R2 keeps the encrypted nightly copies of the database; Cloudflare has no key to them. Google Fonts serves the fonts of the pages. Google, Apple, X, Telegram only if you sign in with them: they learn that you signed in to Macroscope. Browsers’ push services (Google, Apple, Mozilla) deliver pushes if you turned them on. The mail service gets the address and the text of an email only if you turned on the email digest. Telegram delivers the digest if you linked the bot. We sell and share data with no one.
Contact
Everything the site keeps about you, you see and erase yourself in the “Profile” card of the feed.