"From what I've seen so far, it blocks all the 'troll' cheats. Basically, no more equipment spam, no more raining bags, no bag spam, no more of that kind of stuff. The kind of thing that impacts another player in a significant way.
When the system detects a cheat being done, a system message shows up and tells the other players that they cheated (not sure if they can see the message too). Then, a big red CHEATER shows up over their head. Only other players can see it, which means they can choose to leave or say something, or just say nothing.
Basically sort of a warning system for players. I believe it also stops absurd money amounts for the payday."
Example: steamcommunity.com//sharedfiles/filedetails/?id=257814177&insideModal=0
This is what somebody said in the PD2 Steam Forum.