In Anarchy Online no one owns a monster and monsters are open for attack by any player, even if it is already under attack by someone else. The game mechanics work such that the person or team that does the most damage wins looting rights but all attackers gain a share of the experience points awarded for being involved in the kill.
However, there are occasions when repeated kill stealing moves over into the area of harassment. In order for this to be the case there needs to be a clear indication that the person is doing it just to ruin the fun of others. In these instances, it is important for the victim to petition as soon as possible so a GM or ARK can come and handle the situation in a timely manner.
In situations where an alien general, hollow island boss, mercenary island boss or pocket boss is involved, this is automatically considered harassment and is a suspendable offense. The player (or organization) that triggers these NPCs, own these NPCs.