What we collect
Everything SynthStamp sends, and why.
SynthStamp only works if the server has seen what its users see: a repost can only be recognised if the original was seen first. So the add-on sends what the Reddit pages you open show, not only what you tag. Installing it and turning it on after reading this is your agreement. This page lists all of it.
What the add-on sends
| What | Why |
|---|---|
| The text of posts and comments on the reddit.com pages you open, their authors, their links and when they were posted | To show the tags on them, to recognise copied text, and to notice tags placed on brand-new comments |
| A fingerprint of each image and of its mirror image (256-bit PDQ hashes made in your browser), how usable the fingerprint is, the image's size and its web address | To recognise the same picture when it is reposted, resized or mirrored |
| The address of the page you are on | To know where something was seen |
| The tags you make, and when | They are the point: tags are shared counts |
| A random id, made the first time the add-on talks to our server. It is kept in your browser's add-on storage, which your browser may sync to your other devices | So your tags stay yours and one person counts once |
| The Reddit username you are logged in as, when the page shows it | Used only to keep the counts honest, for example to spot someone vouching for their own posts. Seen only by the people who run SynthStamp, never shown publicly, and never treated as proof of who you are |
What it never sends
- Images themselves. Only their fingerprint leaves your browser.
- Anything from sites other than reddit.com. The add-on does not run anywhere else.
- Your Reddit password, your cookies or your votes.
- Your email or name. Those exist only if you make an account on this site.
Your controls
- Collection off. One switch in the add-on's menu stops it sending page content. Account tags still show; they are looked up by a short prefix of a hash, so the server does not learn which account you were looking at.
- Change or remove your own tags at any time by clicking them again.
- An account is optional. It keeps your tags across reinstalls and browsers. Without one, your tags stay with this browser, and with any browser it syncs its add-on data to.
- Delete me. Closing your account removes your email, your name and the other personal details on it, signs you out everywhere, and stops the add-on connecting a name to your tags again.
How long things are kept
Tags and what was seen are kept, with no expiry for now. That is on purpose: if someone could tag in bad faith and then delete the evidence, nobody could trust the counts. When you close your account, your tags and sightings stay under an anonymous id with nothing that names you. What the add-on sends is stored without IP addresses. If you make an account, the sign-in system keeps the IP address you registered and signed in from, for security; closing the account clears it, except from the site's own activity log, which records account changes and sign-ins for security. Our web server keeps ordinary access logs, as any website does.
This page describes the add-on as it is today. Anything new it collects, and every new site it runs on, will be listed here and in the add-on before it is switched on.