Password reuse is rampant: nearly half of observed user logins are compromised

Right... anyone 'observing' my login is compromising it.

Standard feature in cloudflare, checks all passwords going through their endpoints to see if they have been compromised before. Alerts the site admin if it has been. My dashboard is littered with them lol

Paragraphs 3 & 4 describe the (free) Leaked Credentials Detection service they're leveraging for this research.

The article covers that.