Threatening businesses that have made donations in the Proposition 8 campaign on gay marriage has become a weapon used by both sides in the debate. Opposing Proposition 8, Californians Against Hate, created specifically to draw attention to donors who contributed to the measure, organized boycott efforts against some business contributors as reported in the Wall Street Journal and elsewhere., a leading group supporting Prop 8, announced it will publicize any business that donates against the measure unless that company also makes an equal donation to the Yes side. Rest assured, that publicity is intended to be negative.

Asking consumers to be political activists with their dollars is not a new phenomenon. Some have argued it is a good way for people to become active in politics. University of South Carolina history professor Lawrence Glickman argued in a 2005 Boston Globe piece that, “The fact that so many Americans are not only ardent consumers but avid consumer activists suggests that they see consumption not only as a private pleasure but as a public good.”

Boycotts happen in small ways every day. Don’t like what an actor has to say on public affairs—don’t see his movies. It is the organized efforts made to change a business’s way of doing things that get attention. The idea is to have the business back off: Don’t make the donation; don’t become involved in questions of public concern, stick to issues that affect your business.

Many question whether businesses should be involved at all in contentious social issues. Should businesses use their shareholders assets to participate in the campaign when undoubtedly the businesses have shareholders and customers with varying views on issues such as gay marriage?

In the free speech universe, boycotts themselves are a form of free speech, an individual expressing an opinion by choosing not to buy (or the obverse—to buy to support a business’ decision). On the other hand, boycotts can have a chilling effect on free speech by discouraging expression by business owners.

The idea of boycotting and ostracizing businesses has a long history in this nation – in fact, boycotts occurred for political effect when the country began. (The term “boycott” has been around since 1880, when a Captain Boycott was ostracized by townspeople while working for a landlord in an Irish rent dispute.) In 1764, Boston merchants boycotted English luxury goods, and ten years later in response to another successful trade boycott on English goods, Great Britain passed a measure to prohibit the northeastern colonies from trading with anyone from Great Britain and barred colonial fishing vessels from the North Atlantic fishing areas.

This tit-for-tat response to economic sanctions can be seen in the efforts to stigmatize some businesses in the Prop 8 campaign.

Of course, California business is not unfamiliar with boycotts. The grape growers boycott organized by the United Farm Workers is well remembered. More recently, some Southern Baptists organized a boycott against Disney. Boycotts to make political points have been encouraged by Martin Luther King, Mahatma Gandhi and President Jimmy Carter during the 1980 Moscow Olympics.

So what’s a business to do? Stay out of any political fight that doesn’t directly and obviously affect the business? Or take the risk involved with making a stand?

Different business people will take different courses. There is no right answer for all.

Interfering with commerce makes little sense. In fact, most boycotts change little and sometimes cause a backlash against those who promote them. But there is no way people will stop resorting to this tactic.

Therefore, businesses should know the risks in becoming involved in political campaigns. Businesses often proudly trumpet their involvement in the community as being “good corporate citizens.” There is no more important citizen duty than to vote. Since businesses cannot vote, some do the next best thing and try to encourage responsible voting and take positions on measures that may go beyond their immediate business interests.

If businesses choose to be a “good corporate citizen” in this way and become part of the debate, then the business should be prepared for the consequences. At the same time, once making a decision they should stand firm against intimidation. As the saying goes, free speech is never free – there is often a cost to stand up for what you believe.