There's been a directive from top staff, to say he should always be referenced as the "vigilante". I think it makes sense. So far, he's saved people that have been in trouble, via distractions and attacks. He's the very essence of a vigilante.

In all truth, a vigilante is someone who does the right thing, by their own means. Is, they don't wait for the state to control the issue, they tackle it themselves, and end up wanted by the state. Now transfer it to wwe.

HHH is doing the wrong thing; evil.
Sting isn't going to wait for 'the state', is, The authority or Vince to stop it. He's taking it into his own hands.
HHH will now want Sting. HHH is a member of the authority so by definition, the state will chase the vigilante because of the justice he's dealing out.

It's one of the few things I think WWE have got really right since survivor series.