You should just take a recording software , even Bandicam (The free one) works , staff don't care about the watermark , just record a bit of it , 10 seconds min of each of those people hacking , then post on Youtube and then report them , in the report , just put the link of your video . For example -
Name : Hacker
Hacks: KillAura
Proof : <Input a Youtube link>
What I am saying is that posting this on off topics will not help as much as it helps by reporting, they always get notified and can help you faster. This will only get you ignored