Many people do not like fake followers, as they appear to be completely worthless. However, even fake users on twitter follow other real users, and can have real followers – so should you really care? If you think about it, every single follower you got is essentially a free ad for your own account, because people often follow the friends or followers of other users – some even use it as a tactic to gain more followers – should you care? should twitter care?
Fake users on twitter not much of a problem to users
Spam is obviously a problem, but it is not all fake accounts that post spam – many accounts just sit there with little activity going on. Twitter should fight spam, for obvious reasons – but should serious users really care?
Considering that every follower you get has the potential to bring you more followers, perhaps you shouldn't care as much about who or what follows you – just avoid following back the fake accounts. Not that following them back does any harm, but there is no reason to encourage their behavior. If you use auto back-following on your account, then never mind these fakes – what you should spend your time on, is engaging in, and growing your network.
How can fake followers be useful?
A lot of users are using tactics that involve following the friends or followers of other users – fake users or not, being connected with as many accounts as possible will increase your reach trough a number of means.
It doesn't mean you should aim to get fake followers, as they mostly will be useless – you just don't have any reason to feel annoyed by them simply because they are fake. We can start to talk about annoyances when they are mass spamming useless junk.