Not mine, just saw talks about it.
In gang war "Scrappers vs Eels" you can set explosives but don't report about it, and just go and kill Scrappers alone (possible with traps).
After that you can set traps everywhere in Scrappers base, then report that you plant exposive, invasion will start, and fellow SGS members and Eels start to die from your traps, but can never track it back to you.
This is the bug, profitable in classic EXP system.