I have contacted WordPress, and it appears that the false follower problem is widespread and receiving attention. Here are two observations from a WordPress Forum that illuminate a little, and a reply I got from WordPress:
- So my hypothesis about these nefarious Email Followers may be correct: I suspect that, whenever we post a new article in our blogs, these bogus ‘followers’ (probably a bot of some kind) receive a notification e-mail and a bot then adds a Comment on the new article, and that comment would contain spam links.
2) from a WordPress “expert”
Thanks for all the reports. We’re aware of this issue and working block these spam followers. We cannot just block all @outlook.com emails, though, as that will also block many real people from following your sites, so this isn’t just a quick simple fix.
I know this is incredibly annoying, but I also want to reassure you that that’s all it is – annoying. There is no way these spam followers can put your site, your content, or your private account data in any danger. It just increases the number of email notifications WordPress.com needs to send out for each new post, so if anything it’s an attempted attack on us trying to overload our email servers, not on your sites or accounts.
You can remove the spam followers under My Site ->People, but that won’t prevent new follows from coming in. You might also consider temporarily disabling email notifications of new followers in your account settings until we manage to get these blocked. You’ll still see a notification each time in the WordPress.com admin bar, but at least you won’t have your inbox flooded with emails from fake subscriptions.
Please don’t email these addresses back – another potential reason for this is that someone is fishing for emails which they can then use to try and spam directly, and emailing them back will only provide them with your personal email address – something they cannot get hold of by merely following your site.
We’ll update this thread with more details on this once we have them.