Heads up, Creators: On Dec 13-14 you may see a noticeable decrease in your sub count as we remove spam subscriptions. If spam is removed, you'll see a YouTube Studio alert: https://goo.gl/qGDBvX This should help give you confidence that the subs you do have are real fans!
If somebody has gone to the effort of subscribing to a channel you need to leave it alone. Focus on bots. Stop attacking your users and content creators. Why do you care about this if not simply for PewDiePie? I’m not even a fan of his, not am I subbed on YT, but it’s wrong!