The question is, what does "following" do? I can see 3 main things:
1) On the home page you can see a list of people you are following who are logged on. Big deal, eh?
2) The list of people you are following lets you quickly look up those people's profiles and hence whether they have posted anything recently. And of course the list of people who follow you does the same, i.e. you can watch their public activity as easily as they can watch yours (which also means that if you think they are doing anything that breaks forum rules you can report them).
3) In the privacy settings in your profile you can restrict things like who can send you private messages to those you follow (not who follow you). So you can use this system to limit who can send you messages or see your profile page, and as it's people you follow rather than people who follow you you have complete control over this.
I'm not aware of any way of removing followers. But someone who is following you doesn't actually have access to any information that they wouldn't have without following you, it just makes it slightly easier to find: knowing your username and how to operate a search engine they could easily find a post from you, from where they could look up any information you allow any member to see. So I don't think it's a big deal, though I suspect that many people who use it are new and haven't yet worked out how little it actually does.
What I would suggest is that you visit click on your icon in the top-right corner of the page, or visit your profile page, and review yourr privacy settings and check that they are set to what you are comfortable with.
