My issue with Verizon is they lock an account after 3 bad attempts, and the "username" is the cell phone number for the account. Which seems to be slurped into some automated brute force engine.

Every single time I want to login, I have to do a password reset first. Makes me which I had the phone number to every manager in the company, so I could lock them all out every day.

Also, since having the phone is the only second factor for authentication, that's all you need to access an account.