Uh, the Undead have rights too, you can't just go around killing (unkilling?) them, or lopping off body parts! Also, they are not 'zombies', that is racist and ignorant, they are the 'living-impaired', and shall be referred to as an LI-person henceforth.
If an LI-person invades your personal space, you fill in a ZRO-201b form at your local police station.
If an LI-person attempts to gnaw on you, or inflict any sort of GBH, battery or assault, then you can forcibly (but not too forcibly, they are brittle) hold a firm hand outwards towards them, and order them to cease and desist. If they do not comply, you must contact you attorney and ask him to file a UAF-955c with the local magistrate immediately.
If you see a relative, friend, or bystander being gnawed on, or otherwise attacked by an LI-person, you must ask if the bystander in question needs any assistance or intervention on their behalf (be aware, s/he may WANT to be attacked, and you may be interfering their freedom of expression). If they scream or yell at you, ask them to remain calm and state clearly their predicament. Once they explain that this IS an unwarranted attack on their person, you may THEN call the police, or any local authority, and have them come to the location of the attack and serve the LI-person in question a ZUEO-11a blue slip (NOT a pink slip, that is a separate form reserved only for vampir and lycanthrope).
Lets not have anymore "vigilante" justice in this thread, it is racist against the living-impaired and I for one will not stand for it any longer!