Hello, I have seen almost no drop in registering users since I installed this plugin. All of them are from users whose IP address is a webhost, making it highly likely that they are spam users.
I am using the Register IP Multisite plugin that lets me see what the IP of each user is.
All users who are registering are confirming their email address by visiting /wp-login.php/?action=confirm&eckey=[keyremoved] I removed the key for security.
This would seem to suggest that they are confirming their email address, but they have to all be spam users as their IP is a webhost.
I checked my server logs and could see the users visiting the page and then going straight to the registration page. The odd thing is that the registration page is not linked from anywhere within any of the pages they visited, or any other page on my website.
Essentially I think the problem is that spammers have found a way to automatically register and then click on confirmation links within their email. The timings between each page load are so small, it seems to strongly suggest that it is a bot as it is less than 1 second.