Pie Register PRO advanced login security will let you throw CAPTCHA based on the number of unsuccessful login attempts. You can even block IP addresses automatically based on security settings.
The users of Pie Register Pro can edit their login security and setup various features, including, CAPTCHA shown on multiple failed login attempts and locking user accounts on multiple failed login attempts. In both cases, admin can customize its settings as per their security policy.
Ability to show Captcha after preset failed login attempts. Attempts limit set by the Admin. [Premium]
Setup unsuccessful attempt limit after which user will be locked out from login or register for a time set by the Admin. [Premium]
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