How many things is your Gmail account connected to? It is definitely connected to Google+ (which will shut down soon). You might be using your Gmail account as a log in to apps or other websites.
Google says it regularly resets the passwords of Google accounts affected by third-party data breaches in the event of password reuse. According to Google, the strategy has helped protect over 110 million users in the last two years.
Google is now taking password protection one step further. It has created a Password Checkup Chrome extension. When you log into a site (while using the Chrome browser) Password Checkup will trigger a warning if the username and password you use is one of over 4 billion credentials that Google knows to be unsafe.
Obviously, the Chrome extension is only going to work on the Chrome browser. People who use other browsers aren’t going to get any benefit from Password Checkup. One could take a cynical view of this situation and suspect that Google’s main goal is to get more people to switch over to Chrome.
As you may recall, Google has been in the news for doing some very negative things. It recently had its enterprise certificates removed because it used them in a app that sucked up user’s data.
It ended its Project Dragonfly that was, in short, building a censored search engine for China. Google was silent about the bug that exposed private data of hundreds of thousands of Google + users until after the Wall Street Journal reported about it.
There is potential that Password Checkup (which is described as an “experiment” by Google) will improve user’s ability to find out if their username or password is unsafe. I think it will be hard to convince users to trust Google enough to install it.