The problem, as described by Bungie, is that they’re using a “dragnet” approach to catch cheaters in the act, but sometimes the “net” tends to catch a little more than they intended. More specifically, those playing alongside a cheater might find themselves banned, even though they have never used a cheat themselves.
Currently, Bungie are issuing temporary bans to those caught cheating, letting them back into the game after a couple of weeks. Those who continue to cause trouble are then banned for a longer period of time, and there have been reports of the possibility of permanent bans as well.
The fact that cheaters are almost always let back into the game after a short period of time has been taken negatively by most of the community as well, as the majority of players seem to believe that it’s a bad idea to give them a chance.
Most seem convinced that banning cheaters permanently is the only solution that works – and yet, when we look at Valve and their “Valve Anti-Cheat” system which does exactly that, it paints a different picture. There, the permanent duration of bans is the main reason for people to criticize Valve’s measures, and it’s often suggested that the studio relaxes their rules about cheaters a little bit. So far though, this has been unsuccessful as Valve remain firm in their stance.