You may volunteer to do something about it, and in the case of murderers, complete strangers to me may take up the cause, most likely for the purpose of their own safety.

Have you ever read ‘The Moon is a Harsh Mistress’? If so then the trial in that work is a good example of justice without government.

Joe Bully murders you. He is arrested, indicted, and convicted. But then he declares, “I never gave my consent to the laws against murder. You cannot hold me.” Using your logic, everybody agrees and Joe Bully walks free and murders more people.

Anarchy works better than you give credit. The invisible hand of the free market is a good example of anarchy working just fine. Take, for example, what everyone in the country had for breakfast this morning. 300 million people decided what they wanted and just about all of them got it. There is no majority going around saying Tuesday is bagel day and you must comply. Even if there was such a majority, if you wanted a doughnut this morning then chances are you had no problem finding one. People voluntarily consent to all manner of things all the time and it works smoothly. So why disregard this in the name of something that is unethical at its roots?

The majority of the people can never lend legitimacy so long as one person dissents. If the majority were to dicide, 300 million to 1 that you must forfeit your life for ‘the greater good’ then even such an overwhelming majority is acting unethically.

Mises has recently reprinted a piece on this subject.
http://www.mises.org/story/2624

When it comes to government I cannot think of an institution that has deliberately killed more people for the shallowest of reasons.

You seem to think that without government, things would be just hunky-dory. The historical record is quite clear on this point. There is no case in history in which government was entirely eliminated; in every case where government disappeared, strong men appeared and used violence to establish their own government. And in those cases where the overall rule of government declined, so did the population.

You’ll never get me to agree that consent can be assumed by government (that would be too much like a divine right) or that it can be implied (which is unethical).

Stefan Molyneux explains better than I do:
“Furthermore, it is hard to imagine how just living in a country creates any form of implicit contract with the government. Implicit contracts are by their very nature unjust –and how do we know this? Because private citizens are not allowed to create and enforce implicit contracts. I can’t say to my neighbor that his decision to live in his house automatically requires him to mow my lawn. I can’t buy a car, offer to share it with my neighbor and then force him to pay for half of it. Anything which is unjust for private individuals is also unjust for those in the government – since the government is merely composed of individuals, and thus must be subject to the same moral laws as everybody else. Any rights or abilities claimed by those in power which directly oppose the rights or abilities of everybody else are automatically unjust and immoral.”
http://www.lewrockwell.com/molyneux/molyneux17.html

My expectation of the Constitution is not to grant me anything (especially such things I do not consent to). The idea behind a legitimate limited government is to protect people from the predations of unethical men and not to become the vehicle for such predations. If I must amend, violate, undergo legal penalties, or depart from a territory to secure my life and liberty based on implied obligations under the Constitution then the claim to ‘secure the blessings of liberty’ is an outright lie. The Constitution, which should protect my inalienable rights, becomes the hammer with which to destroy them.