recent clone hero cheating admissions

can someone explain this to me? i only recently started getting into CH and basically only know acai.

who cheated, and how was it discovered?

where are people migrating to? is YARG safe from cheaters?

and finally totally unrelated: i don’t know why there is a GH2DX, RB2DX and RB3DX but seemingly no GH3DX. can someone fill me in? is there something wrong with GH3?

sorry for a pretty dumb post, just trying to spark some activity on here