Evaluating e-mails urging people to participate in some form of protest is always difficult, because (except in the rare cases where a hoax or a joke has been taken seriously) they can't be "true" or "false." The protests may succeed, fail, or achieve some intermediate result, but whether to participate is a matter of individual choice. We don't know who came up with the idea for the Not One Damn Dime! protest (it is often falsely attributed to newsman Bill Moyers) or what level of participation it might achieve; all we can do is offer an opinion about its likelihood of success. In this case our opinion is that someone has taken the futile concept of slacktivism to a new extreme.
Some protests are functional; they involve people taking direct action to achieve the desired result, such as chaining oneself to a tree to prevent its being cut down. Other protests are symbolic; they seek to inform the public or call attention to an issue through activities such as holding marches or making speeches. Sometimes protests are a combination of the two: chaining oneself to a tree is a functional but necessarily short-term solution, yet such an event is usually covered by the media and thus helps to publicize the cause of conservation.
So which form of protest is this supposed to be? Its ostensible purpose is a symbolic one — to "remind the people in power that the war in Iraq is immoral and illegal" — which leaves us wondering how this form of protest is supposed to help effect any change in circumstances The merits and conduct of the U.S. war with Iraq have been endlessly debated, in every medium, since the U.S. invasion of Iraq nearly two years ago. The war in Iraq was the primary issue in a long, contentious, headline-dominating presidential campaign that ended just a few months ago. The war is still one of the lead stories in the news nearly every day. Many different polling organizations and major news outlets regularly survey public opinion on the issue. If the result desired by those who would engage in this protest hasn't yet been achieved, it's not because the issue hasn't received enough publicity or those "in power" are insufficiently aware of it.
All that aside, the suggested scheme is one of the least effective forms of symbolic protest one could devise: it literally proposes that people do nothing, and doing nothing generates little, if any, publicity or news coverage. Massing thousands of people in one place and engaging speakers to make rousing public speeches provide vivid, well-defined images for the news media to pick up on, but pictures of people not spending money just don't make compelling fodder for newspapers and television. (Images of normally bustling malls, restaurants, and airports standing eerily devoid of human traffic might make for a good news story, but public opinion on this issue is far too divided for this protest to be able to bring all business to a grinding halt.) Even worse, when you call upon people to do nothing, how is anyone supposed to gauge the success of your efforts? There's no way to distinguish those who are doing nothing out of principle from those who are simply doing nothing out of habit.
As a functional protest, this one is equally off the mark. Although a boycott can be an active form of protest (even though boycott participants are in effect doing nothing, they're following a course of action that directly affects the object of their protest), boycotts succeed by causing economic harm to their targets, thereby putting them out of business or at least requiring them to change their policies in order to remain in business. But the target of this boycott isn't an entity that has the power to bring about the desired resolution (i.e., the government) — those who will be economically harmed by it are innocent business operators and their employees. These people have no power to set U.S. foreign policy or recall troops from Iraq, but they're the ones who would have to pay the price for this form of protest, incurring all their usual overhead costs (e.g., lighting, heat, refrigeration) to keep their businesses open and paying employees' salaries, all the while taking in little or no income. (And no, it doesn't all even out in the end — restaurants, for example, aren't going to recoup their lost business through boycott participants' eating twice as much the next day.)
Whether the desired goal is laudable or not, a protest that has little chance of succeeding at its purpose but a high likelihood of harming innocent parties does no one any good. As we always say about these kinds of things, results are generally proportional to effort: If the most effort one is willing to put into a cause is to do nothing, then one should expect to accomplish nothing in return.