Gives you the ability to temporarily disable user accounts without having to delete them.

The ability to mark specific users as spammers like on Multisite install.

Allows BuddyPress administrators to block users indefinitely, or for a specified period of time.

The most advanced protection against sploggers and spam users registration, is fully WordPress,WordPress MU ,BuddyPress and bbPress 2.0 compatible

Advanced security logger designed to protect your WordPress from hackers. It allows you to look at live logs of your website and lets you detect malicious activities. There are multiple security features of this plugin that you can explore to keep your WordPress secure.