It is the Subscription widget found with the Jetpack.
The thing is I have over 50 Followers, none of which appear in the administrative back-end as a User. The subscribers to the site are listed in my email registry and have valid names and email addresses and they can do is get new post notifications and comment on posts.
The Email list can be found in the Jetpack > Site Stats > Subscriptions >Followers > Blog
These are Hackers from Poland
Username: fiz2xsf
E-mail: [email protected]
Username: zgt9gkjc5
E-mail: [email protected]
Username: rt9js28
E-mail: [email protected]
Username: p37r4k8
E-mail: [email protected]