Similar experience here. Years ago I got emails from Mozilla for a few days in a row about failed login attempts to my account from a certain IP. I did a WHOIS

Similar experience here. Years ago I got emails from Mozilla for a few days in a row about failed login attempts to my account from a certain IP. I did a WHOIS on that and I obtained that it belonged to Fastweb, it was likely some household's dynamic IP. I emailed the listed Fastweb's abuse email address a couple of times, but never got any reply. The login attempts stopped, but I would say probably because whoever was doing it figured out they weren't able to guess my password, not because Fastweb actually did something about it.