On Safer Internet Day, that took place on 5 February 2019, Google Chrome, in collaboration with cryptographists from Stanford University, released a new extension named 'Password Checkup'. THe extension checks username and password combinations entered in login pages to be placed in a Google database of four billion credentials compromised in data breaches. The extension is aimed to mitigate negative consequences of massive breaches like Collection#1. Password Checkup will not alert a user when they use unsafe and simple passwords, but when the username and password have been previously breached. Moreover, the extension is designed in a way that Google does not learn user passwords and keeps the breached credential database protected.