Ideally, this plugin is supposed to hide the @username still used in BuddyPress and replace it with the nice name generated from the first and last name of the respective user. Unfortunately, that no longer works. The plugin correctly replaces the first username found with the beforementioned string, but all other usernames are replaced with @first_last_n where "n" is a digit added automatically by this plugin. So if you have 5 users the user's nice name would be "@first_last_2", "@first_last_3" and so forth. In general this doesn't defeat the general purpose of the plugin, but it doesn't work 100% as described.

great plugin for security concept, it hides user's usernames completely from frontend of the site...