Question: We are told in the Torah that certain actions will cause “karet,” i.e., that the person will be cut off from the nation. What about those Haredi fanatics who are harassing people and vandalizing property? Shouldn’t that earn them “karet” as well? Why should they continue to be part of our nation?
Answer: The question is an interesting one, but before answering, I think it is important to define our terms before we venture forward. Once we define the terms, we will then examine whether or not karet is really applicable with respect to the Haredi behavior.The term karet literally means, “extirpation,” “cut off,” or “cut down,” and is related to the Assyrian word, karâtu, which conveys the same idea of “cutting.” The notion of karet implies being “cut off” from the community of Israel.
As to the nature of being “cut off,” this is a matter of discussion.
Rabbinical tradition lists 36 types of transgressions that effectively “cut off” the soul from its spiritual root—God. Some early rabbinical texts view the act of excision meant that the sinner would not live to see his 60th birthday, but others think the offender may live up to 70. Should a sinner not die in the assumed time periods mentioned above, the fear of an imminent death probably exerted a frightening effect on the offender’s psyche.
The rabbinical perspective on karet resembles the type of punishments described in Greek mythology. Notions of eternal damnation as championed by Nachmanides, who believes the soul is cut off from God even in the world of Eternity, strikes a modern person as excessive.  Maimonides believes that God denies the wicked sinner’s soul in the hereafter.  However, the Talmud does say the power of repentance and the Day of Atonement can suspend the heavenly punishment, and erase all vestige of sin.  Support for this perspective may be found in the Tanakh itself, “Cast away from you all the crimes you have committed, and make for yourselves a new heart and a new spirit. Why should you die, O house of Israel?For I have no pleasure in the death of anyone who dies, says the Lord GOD. Return and live!” (Eze.18:31-32).
There is another way of viewing karet that the Talmud and the medievalists did not consider. Karet has nothing to do with being “cut off” in the eternal sense from God. Rather, it is a form of ostracizing. In a culture where individual identity was defined in terms primarily of the household group to which the individual be longed, karet may have originally meant social ostracizing from all aspects of community life. In pre-modern societies, being a member of the community strengthened both the individual and society as a whole.
Ostracizing meant the offender would have no social relations with his family, friends, business relations, and social network. Such a penalty must have seemed like death itself. Apart from the community meant being cut off from the deeper reality of life that connects the soul to God. Being cut off had practical consequences, e.g., the loss of status and social privileges. The Christian and Jewish practice of excommunication may well have been inspired by the karet concept. The underlying theme in karet seems to focus on the maintenance of certain religious boundaries that have an important impact on the corporate character of the nation. The social implications of someone who did not practice ritual circumcision meant the family would not have anything to do with the son who separated himself from the religious and spiritual traditions of his family. It is no accident that karet is sometimes used as a metaphor for divorce (See Deut. 24:3).
With these thoughts in mind, let us return to the your original question regarding the Haredi community. Notions of karet as defined by the early rabbinic standards do not apply to the Haredim. Today’s Haredi separatism derives from personal choice; they do not wish to have any contact with the non-Haredi Jewish community. They alone have cut the ties that bind them to the Jewish people.
This attitude can be seen in many ways, for example: Their leaders encourage them to destroy all their home-computers, as well as all phones that have wireless connections to the Internet. Others believe that the pursuit of a secular education is sinful, since it comes at the expense of giving up Torah study. They also believe that the Rebbe or Rav’s authority is infallible.
Although Haredim receive billions of dollars for their institutions, their separatist theology keeps their followers impoverished. On the one hand, they hate the State of Israel, but on the other hand they demand that the State continue supporting their lifestyle! To use another analogy, Haredim often behave like a spoiled adolescent girl who says, “I hate you Mom! Now, will you please drive me to the Mall?” The Israeli government needs to practice some "tough love" with the Haredim. The American Jewish community must make its financial support for Israel contingent upon Israel protecting the rights of all of its citizens.
Haredi leaders have not come to terms with the fact we are living in the 21st century. Many of them are uncomfortable by the religious and spiritual challenges of living in a contemporary world. Too many of them wish they could turn the clock back to a simpler time when the modern world did not matter. Cutting them off from the Jewish people is not a solution. Rather, the State needs to diminish its financial support of their institutions, and impose taxation upon them like everyone else, and insist that its young people join the army.
 Mishnah Bikurim 2:1
 See Ramban’s Commentary to Lev. 18:29 and in Sha’ar ha-Gemul.
 Maimonides writes, “The punishment of the wicked is that they do not merit eternal life, but they suffer karet and die” ( MT Teshuvah 8:1).
 “For what transgression does penitence procure atonement? For that of a positive commandment. And in what case does repentance suspend punishment and the Day of Atonement procure atonement? In such as involve extirpation, death-penalty through the Beth din and in actual negative commandments” (BT Yoma 86a).