When it comes to the issue of whether or not it is ok for someone the knowingly aid someone in breaking an agreement I feel it depends on the risks at stake for people not knowing what the person has to say. For example, if I had an agreement with a co-worker to not tell anyone that I had cancer I would be very angry if someone coerced that person into telling everyone. But on the other hand if I made that person promise not to tell anyone about a possible danger to all the other workers and someone coerced them into saying something it would be far better for all the workers to know about a possible danger even if I did not want them to know. In other words the happiness that comes from the workers knowing there is a problem and being able to fix it would far out weigh my anger towards the person who broke the agreement. In the case of big tobacco I think there is a difference. People already know that smoking is bad for you and can cause lung cancer but they continue to smoke.
The idea that because the people now know that big tobacco adjusts the levels of nicotine in their cigarettes does not mean people will be angry enough to quit. The only reason why it would be important to know that big tobacco adjusted the levels of nicotine in their cigarettes would be in order to sue them for the fact that they knowingly try to get people addicted to a product that will kill them. But that money should be going to one place and that would be to pay for all the doctors bills of the people dying of lung cancer from being addicted. Utilitarianism would have to agree that the happiness of the people that don't have to pay more taxes to support the people on Medicare or welfare who are dying of cancer from smoking far out weighs the loss of happiness of the workers of big tobacco. Besides, big tobacco has enough money to pay all of the lawsuits and still come out on top. The sad thing is the government is basically becoming big tobacco because with every lawsuit the prices of cigarettes goes up, but does that mean that smoking has decreased? No, it has actually started to increase among teenagers, more than 1.
2 million Americans younger than 18 started smoking in 1996, up from 708, 000 in 1988, according to numbers released by the Center for Disease Control in the fall of 1998. Utilitarianism might actually favor not blowing the whistle on big tobacco because all that is happening is the government is just taking advantage of cigarette addicts and that makes them no better than big tobacco. I know that I am no happier now than before big tobacco lost all of their lawsuits because me, and millions of other Americans, have not seen any of that money; whether through tax cuts or, being in the Seattle area, road maintenance. I think the hit cigarette smokers take to their wallets, by the increase in prices, creates for more unhappiness than happiness.
Kant would say, no an agreement cannot be broken because then you could never make an agreement in good faith. If everyone went around breaking their agreements the world would be a terrible place; therefore, in all circumstances agreements must be kept no matter what. If airing a story on big tobacco might damage you financially I think you do need to be guided by the public interest. But in the case of big tobacco I don't think it was that big of a deal because the public already knows that cigarettes are addicting and that they will kill you. Whether or not big tobacco adjusts the levels in their cigarettes is not that big of a deal when the other aspects of cigarettes are already well known. The story only seemed big for the people who could profit from it.
You would have to measure how much of the public interest is at stake before making the decision, and in the case of tobacco the public knows everything it needs to know to make an intelligent decision of whether to smoke or not.