The 23andMe breach in 2023 affected 6.9 million people. How did the attackers get into those accounts?

23andMe was not hacked directly. The attackers used credentials already stolen from other breaches and simply tested them on 23andMe accounts. They worked because millions of customers had reused the same passwords across multiple sites. This is exactly why password reuse is so dangerous: a breach somewhere you have forgotten about can unlock an account somewhere you care about deeply. The result was 6.9 million accounts accessed, a $30 million settlement, and a bankruptcy filing.