Viking society was self-regulated. Law and order was based upon the Thing system, which had already been established via common-meetings dating to least 600 AD. The Thing had legislative and judiciary powers. Every free man had a duty to meet at the Things common-meetings, except men who farmed alone and were unable to leave their farm unattended. Also, women and handicapped people could attend the Thing. Among other items, the Vikings elected their King at the Thing. These common-meetings might last several days, therefore the Thing was also an occasion for a large marketplace and festival.
The Vikings had no written laws. However, a man referred to as a "lovsigemann" - in English this means "law reader man" - opened the Thing by reading the laws, which he had memorized by heart. This was done to ensure that no one changed the laws. Every free man had to respect the law , including chieftains and the king. The Thing was a democratic constitution. Compared with the democracy of ancient Athens, which included only 10% of the inhabitants as citizens, the Viking system was more democratic. It included everybody as citizens, except the slaves and those exiled from society - the outlaws.
Viking society was permeated by their religion, although the Vikings had no word for "religion". Instead they used the word "siðr", which means custom or practice. However, the moral code in Viking society was not directly tied to having a belief in the gods. Social behavior was based upon an unwritten system of honor or code of ethics. Right and wrong, gender roles, sexual morality, daily life, the timing of festivals; in all these circumstances the free man was evaluated by standards of honor.
A man of honor was a principled man. He was given to moderation, was hospitable and generous and offered a helping hand to friends in need. (Including aligning himself against his friends enemies). A man of honor also never forgot to be the foe of his enemy. This he did with all his heart.
The opposite of honor was disgrace, and because every man lived his life as a member of an extended family-circle, he could easily bring disgrace to his entire family - including his forefathers. Therefore, it was intolerable for a free man to live in such a fallen state. If he was disgraced, he could only restore balance in his social system by confronting the source of his fall from an honorable status. Thus, revenge was an key component of this social system, a system which placed great importance upon maintaining personal honor.
The typical view of revenge was present in the old adage: "A slave takes revenge at once, a fool never takes revenge" . A good man, however, simply waited. He left his victim unaccosted for a long time, up to several years. Then, just as retaliation seemed to be forgotten, one day he would suddenly attack his enemy with a masterful stroke - hard and inexorable.
Through the ordeal of waiting the good man showed his strong character. This long waiting and the coolness of the fulfilment of the revenge may appear to us as cruel and heartless, but we have to remember that the threat of blood vengeance was the Viking society's only effective punishment. It was only through the good man's composed way of enforcing the revenge, that revenge became an genuine judicial authority, and not merely a primitive and vindictive act. There was, in other words, an ethical societal code in the private claim of a delayed and resolute revenge.
The explanation for the frequent in-fighting within Viking society lies not with a lack of respect for the law among its members. Rather, the basis was provided by the tension of living in a society which placed a premium upon maintaining personal honor. Men therefore took the requisite action to maintain honor or ward off dishonor. Revenge was a mechanism employed by individuals or families to maintain a positive balance in their own lives. This is the background for the many bloody fights written about in the family-sagas and history books.
My Dunkin Donuts fiasco. I'm officially blaming on you. 
or 
(you know who that is for btw)
