Dont know if someone suggested this already, but I had the idea when I saw people at MMD killing guards for no reason.
At first to get more depth in PvP make all areas at least 25%. This would prevent the borderjumping/hiding and would give the faction war more sense and depth. I guess higher level would appreciate it. Towns and newbie hunting areas should be heavily guarded and protected by guards (lvl 180-250). If that doesnt prevent higher level player from killing lower level and if the guards aint fast enough to protect the people there against higher intruders, make the guards able to cast 'Arrested by Guard' on a killer.
This Nano has the ability to root (not as normal root) the killer for the amount of minutes which are the difference in lvl of the killer and victim. I.e when the killer is lvl 180 and the victim 75, the killer is arrested for 105 minutes playtime and if it is a gank, like 3 on 1, everyone who shot on the victim and and in range of the guard is arrested for the highest difference. But you might get a chance to escape, if you make it in the casting duration out of the range of the guard.
When arrested, guards quit fighting, the gun and armor is dropped to the inventory and cant be equipped for the arrest time. Animation looks like you stand there with handcuffs on. You can get killed by other people and that would probably happen.... but guards would try to protect you and if someone kills you he get the same arrest.
Dont know if an ability of 'Breaking Arrest' should be implemented. That could depend on very high B&E skill and CL for a hacker tool. Just use it on yourself and when your B&E/CL is high enough you can get out of the Arrest. If you are successful, the guards try to Arrest you again - if in range.
This 'Arrested by Guard' can also be executed when you kill a guard and an other is nearby.