UniversalNotes от Amal S Palackal

UniversalNotes is an open source, non-profit browser extension that lets you add "notes" to web pages with important context about them, which can then be viewed by other people when they visit those pages.

These notes could provide additional context to a misleading page, or news article. They could also alert people by noting that a specific website is a scam, and back it up with reliable sources for the claim.