First of all, the old as the time question: Whom to blame?
There is something wrong in Drifters, they never state their demands and just going for what they want without even trying to trade for that: in many cases trade gives you what you want for less used up resources than military solution, that usually becomes way more expensive and used only in extreme situations. That makes me think that they might not be as sentient as some researchers claim. For me their actions look like they’re automated defense system that got artificial intelligence and now just attacks what threats them.
As scope has mentioned they’re being more inclined towards “hunting down and destroying individual pilots”. With that comes question: whom exactly do they kill? Did their victims attacked sleeper structures in wormhole space? Did they attack Drifter hives themselves?
I think it will be profitable if we can categorize offenses against Drifters and make a database of persons wanted by Drifters.
Could they also be responsible for increased activity of Drifters and following Blackout? Punishing them might help lift the blame from CONCORD and somewhat pacify nullsec crowd in case they are planning any riots or worse.