Re: How to control spam registration?
FYI, Today I updated SI CAPTCHA Anti-Spam for latest version of buddypress 1.2.3 compatibility
SI CAPTCHA Anti-Spam
https://wordpress.org/extend/plugins/si-captcha-for-wordpress/
This plugin adds CAPTCHA anti-spam methods to WordPress on the comment form, registration form, login, or all. In order to post comments or register, users will have to type in the code shown on the image. This prevents spam from automated bots. Adds security. Works great with Akismet. Also is fully WP, WPMU, and BuddyPress compatible.