WPMU reCAPTCHA
WPMU reCaptcha (A WordPress Multisite Plugin)
Install
No release zip yet. The repository archive installs, but the folder name will carry the branch suffix and updates will not flow:
wp plugin install https://github.com/belkincapital/wpmu-recaptcha/archive/refs/heads/master.zipAdd reCAPTCHA to your login pages. Works for WordPress Multisite. Please Network Activate this plugin. Only 1 api key is needed from Google as long as you do not domain map the wp-admin (backend) of your subsites.
Demo: http://psmutheme.com/wp-login.php
Important
After downloading from Github, you MUST rename the plugin from wpmu-recaptcha-master to wpmu-recaptcha so it sits like this wp-content/plugins/wpmu-recaptcha/wpmu-recaptcha.php to avoid any potential issues. I'll fix this later on so you wont need to rename it, but for now you should rename the plugin's folder to /wpmu-recaptcha/ then upload it via ftp, then activate it.
Compatibility
This plugin was create for WordPress multisite. Already tested on a MU network of 900+ subsites. At this time, this plugin does not work on standard WordPress sites. This is a MU plugin and is intended to be network activated.