Obviously HAC2 is available to anyone that downloads it, it is very useful to enable the automatic map downloads in Halo CE.
I was in another server (not BK) on the opposite team to a n d y and his chat made it obvious that he was tracking me using Sight Jack (f7). I asked him to double check and he openly admitted that he was using Sight Jack to track me. Later that day he did the same thing on the BK ROK server.
He seems to think it is ok for him to use it because it is a 'normal' part of HAC2. When I explained to him that HAC2 stands for Halo ANTI Cheat 2 he called me a loser and rage quit