PHILOSOPHY – Utilitarianism isn’t as fair as it initially seems
Utilitarianism as an ethical philosophy can simply be defined as a system in which 'the theory that the rightness or wrongness of an action is determined by its usefulness in bringing about the most happiness of all those affected by it.' (http://plus.aol.com/aol/reference/utilitar/utilitarianism?flv=1&flv=1&icid=algo.encyclopedia.M.xml). There are various versions of utilitarianism. For instance, the original formulation by Jeremy Bentham identified utility in terms of maximising pleasure and minimising pain, whereas Singer's version identifies the goal as a more general satisfaction of interests, whether they are hedonistic or otherwise. Positive utilitarianism focuses on the maximisation of pleasure and negative utilitarianism on the minimisation of pain. Act utilitarianism is when the effect of each action in turn is calculated in each individual situation, rule utilitarianism is when a general rule for behaviour is decided based upon its effectiveness in most situations. Utilitarianism is allegedly the foundations of our legal system, so it is important to ask ourselves whether it is actually fair or whether some are denied the simple right to have their own interests respected.
Tyranny of the Minority
Although utilitarianism seeks to create the greatest happiness for the greatest number, it recognises that as happiness is a subjective value, it can only be determined by the individual. An individual will discover what makes them happy through a series of learning experiences, a process that can never be properly replicated by the state or wider society.
Once we have learned what makes us happy, utilitarianism fosters this by encouraging a non-interventionist approach to morality. In other words, no one is justified in interfering if a person's actions are self-regarding. They have no impact on anyone else, so it is up to them to determine their own morality.
Therefore, contrary to the assertion that "this is unfair to people who...don't agree with society's norms", utilitarianism is the perfect system for ensuring the rights of minorities are respected and not left vulnerable to the mob. While I agree with your sentiments on the dangers posed by tyranny, I fear you have misunderstood the nature of utilitarianism.
INDIVIDUAL HEDONISM NOT ALWAYS POSITIVE FOR SOCIETY/INDIVIDUALS THEMSELVES.
Individuals need to suffer in order to live a full life and there are many circumstances where people should not feel happy, e.g. when grieving the dead.
Utilitarians had never heard of masochists.
Impossible to apply to non-humans
Happiness and sadness are such broad concepts that they can be attributed to anything even the Earth as a whole.
What is utility?
Why? Because it is unclear whether "utility" refers to:
a) solely to individual (normative) preference, which, especially in aggregate, tends to be rationally inconsistent (see any basic principal of revealed preference economics example). This leads to poor (see confused) decision making long term because the aggregate makes inconsistent choices.
b) some objective list of criterion of which utility is a function (like say education, nutrition, fitness). The trouble is that in an inherently pluralistic world, such an "objective" list is nigh impossible to obtain. It is also difficult to know, objectively, what is good for us. It is folk-knowledge that what we want and what is best for us do not always (or even often) meet.
This confusion over what "utility" means creates a scenario in which whomever holds the reigns of power decides what "utility" means for everyone. It is not much of a stretch to say that this is a sub-optimal situation. By subscribing to a purely utilitarian philosophy, one more or less ensures a sub-optimal outcome in utility due to the practical implications of such calculus.
Morally Troubling Outcomes
Say we have one person strapped to a machine where all we need do is push a button and they will die. The mastermind of this experiment will poke you with a stick if you do not push the button. Do you push the button?
Obviously not. The utility you lose from being poked with a stick does not equal the death of another human being.
But what about 100 people being poked by sticks? A thousand? A million?
At some point, the disutility of the masses being poked will outweigh the utility of keeping the person alive.*
If this conclusion seems absurd, that is because it is. Clearly utility does not "aggregate" in such a manner that a minor inconvenience times a thousand (or a million, or even a billion) can equal the murder of a human being. Yet this is precisely how utilitarian thought functions. Without this additive quality of utility, the theory becomes meaningless. With this quality, it produces absurd conclusions.
*Some would probably like to counter that you can assume that disutility of death is infinite. However is this were true than a utilitarian system would be paralyzed if any decision it made would result in the death or suicide of a person. Clearly this is nonfunctional.
If Utilitarianism in its strictest form were to be applied throughout, Gays, Transgenders, even disabled people would be outcasted or even murdered to keep the "greater good" tothe majority.
I am proud to be in a society which is trying to promote positive attitudes to different ways of life.
draws upon basic human needs
Causing pain (via emotional blackmail or wartime torture) is a means of getting what you want(fulfilling interests) from other people. Fulfillment of interests, again this could involve stepping on other people's interests.