^^^^ THIS ^^^^
I've wonder about those "robots"?
I'd hate to say this because it would add another step to logging in, but adding a CAPTCHA would wipe those bots out.
CAPTCHA helps to an extent. I follow alot of cyber security stuff because I do alot of online gaming and CAPTCHA helps to an extent. The newest and more effective ones actually have you do a 'puzzle'. Bots can easily do word based ones, but it's harder for the puzzle piece ones.
Personally I like the authenticators that use my cellphone for log ins :)