If the "Add a block on Steam Store displaying online stats" option is enabled, the extension will do a secure request to steamdb.info to get the current amount of players and last depot update (the latter only if "Display last depot update on app pages" option is enabled). These requests are cached by Cloudflare and may not even hit our origin server in most cases, if they do they are not logged.
If the "Highlight owned and wished products on steamdb.info" option is enabled, the extension will request some user data (wishlisted products, owned products, products in cart, ignored products) from the Steam store via https://store.steampowered.com/dynamicstore/userdata/ and will use these to apply highlights on the site. This is contained entirely within your browser and is never sent anywhere else (including us). To prevent excessive requests to the Steam Store, your user data is cached in localStorage.
Every other option is contained per domain the extension works on (store.steampowered.com, steamcommunity.com and steamdb.info) and never leaves those domains. It is also open source (https://github.com/SteamDatabase/BrowserExtension) and as such its code can be reviewed for accuracy of this notice.Last update: 2018-09-01