No. That's the ultimate way of abuse, and I sw that on other games. Ruins everything and is not fun (not fun for the victim, because the attacker is happy ruining all). High level trolling people by kiling them? No thanks. This games is not for that.

Example:
"Are you waiting for a node to spawn and gather it? Oh, would be a pity if I kill you when pop..."

Player kill will cause only problems. What about the poeple like me who don't want be attacked by other while is playing alone on my things? Or the low level newies being abused by others? Player kill is a stupid way of fuck everyone fun. YOu only need few trolls to turn all into a shit.