At the moment there is a ridiculous bias towards the griefer/PvPer. The potential cost to the victim is huge and the cost to the aggressor is negligible.
FD needs to address this balance to make piracy and general griefing an incredibly risky proposal where there's an very good chance that you will be caught and destroyed, or make it much harder to function, like any criminal would need to do.
On a side-note, current PvP "piracy" is essentially a bogus "legitimizing" of griefing since "Give me your cargo" piracy is a monumentally pointless exercise since the income is minimal and time expended excessive (if you actually pick-up the dropped cargo!).
Criminals want money, not useless cargo canisters, so some kind of "blackmail" system needs to be implemented (give me $250k or I destroy you), but this goes completely against with the desire of FD to make credit transfers as hard as possible.
My gut reaction would be that murders are automatically punished with the removal of all insurance coverage (do real criminals get insurance??), or maybe a sliding scale where insurance gets more expensive with each murder. This would be a huge deterrent to those that casually grief, and make it a much more dangerous occupation.
I think ED needs to figure out what they actually are trying to achieve here. It seems they are trying to cater to two different types of video games, an arcade space shooter, and a immersive space sim. I don't think you can have your cake and eat it too. The easiest way to balance this would be IMO ( their are other valid ways to do this...), make ship repairs cost something again, etc.. etc.. Make ammo cost more, quit giving out the fighter ships at a dime each, make rebuy costs excessively more expensive, remove the massive credit making exploits. etc.. etc... Right now the issue is PvPers make far to much to easily and are able to buy their ships at excessively lower prices then traders etc.. etc... Basically Piracy is not balanced to traders. It is extremely one sided. When Your Haulers w.e have no real chance of fighting off a Viper, as well as the price difference being somewhat massive.
But in all honestly people who are complaining about griefing. Here is an example of real griefing that could be possible in ED.
All these people doing the 'buckyball run' to Sag A* what if I went out their with 5 of my friends and stayed about 2 or 3 jumps from destination and just poped anyone that came into that zone. That could be days of your work gone instantly.... someone randomly killing you while you flying around hauling goods is nothing.... NOTHING......