From my understanding of how Karma will work is based on tracking states when a player kills another player.
If a Pirate player interdicts a trader player and extracts cargo from them without a kill then thsi is just the standard bounty for interdicting/ shooting lasers/ hatch breaking etc. Nothing would register on karma.
If a Pirate player interdicts a trader player, who refuses to comply to demands, engages in combat (or refuses to stop) and is then destroyed I belive that thsi would be a tracked instance that would contribute to karma.
Factors when a karma event occurs may include, Combat rating of killer and victim (massive disparity is being looked for), ship value (to compare for eagle ganker vs T9, or Corvette Pirate vs Sidey "trader" again massive disparity)
Now doing one of the above does not necessarily mark you for death, it just ticks up teh karam rating to something where possible sanctions may come into play (high security are hostile, rebuy is larger etc etc).
It is also understood that these sanctions will be gradual, so killing a T-9 with an eagle does not immediately result in 100% rebuy, no access to any Lawful systems and a shadow ban for 6 months. I would assume that anything as draconian as shadow ban would require Frontier adjudication and the other sanctions would apply gradually over time if players karma continued to degrade.
The other part that forum contributors seem to miss is that there must be a way for karma to be buffed. Lawful activities like handing in missions, bounty and combat vouchers may demonstrate that you are on the straight and narrow and should in some way mitigate bad behaviour, but not in such a way that you can kill a player then hand in 1,000,000Cr of bounty and that issue is cleared. It may be that like a criminal conviction any bad karma is always there as "previous" to help spot the players trying to game the system.
I think the challenge Fdev are facing with this is that its tracking actions that may be "honest" or accidental or planned and it has to have a way to set a target that will start punishing players that continue performing antisocial escapades, on the flip side it should also track good behavior and possible provide a positive karma rating that also enhances player rewards for complying with the law (less rebuy, bigger mission rewards, free engineer materials, automatic docking requests provided).
I am looking forward to whatever gets implemented as hopefully it will add an interesting challenge to pirate play as well as add consequneces for both anti-social and social play styles.