Of course this is not a brute force attack, credentials stuffing is different from bruteforcing and I am well aware of it. What I am saying is that the “lockout period” or the rate limiting (useful against brute force attacks) for logins are both security measures that are sometimes demanded from companies. However, even in the case of bruteforcing, it’s the user who picks a “brute-forceable” password. A 100 character password with numbers, letters, symbols and capital letters is essentially not possible to be bruteforced. The industry recognized however that it’s the responsibility of organizations to implement protections from bruteforcing, even though users can already “protect themselves”. So, why would it be different in the case of credentials stuffing? Of course, users can “protect themselves” by using unique passwords, but I still think that it’s the responsibility of the company to implement appropriate controls against this attack, in the same exact way that it’s their responsibility to implement a rate-limiting on logins or a lockout after N failed attempts. In case of stuffing attacks, MFA is the main control that should simply be enforced or at the very least required (e.g., via email - which is weak but better than nothing) when any new pattern in a login emerges (new device, for example). 23andMe failed to implement this, and blaming users is the same as blaming users for having their passwords bruteforced, when no rate-limiting, lockout period, complexity requirements etc. are implemented.