Secondary boycotts in the age of social media can be arbitrary, capricious and poorly thought-through, but that doesn't mean they should be stopped, writes Chris Berg.

There's a saying you hear often in libertarian circles - a government big enough to give you everything you want is a government big enough to take everything away.

Consumer and environmental activists ought to start thinking about this too.

On Monday, the new federal parliamentary secretary for agriculture Richard Colbeck told The Australian that the government might ban consumer and environmental activists from launching secondary boycotts.

For example, in 2011 GetUp tried to organise a boycott of companies that were members of the Australian Food and Grocery Council because the council had said Julia Gillard's carbon tax would increase manufacturing costs.

The issue will be considered in the long-promised review of one of the most complex and problematic pieces of Commonwealth legislation - the Competition and Consumer Act 2010.

The Competition and Consumer Act is a 1,500-page behemoth of regulatory complexity. It empowers Australia's most imperial regulatory agency, the Australian Competition and Consumer Commission.

First introduced as the Trade Practices Act in 1974, the act has been continuously expanded at the behest of consumer activists in and outside government.

Now it seems this labyrinth act is to be turned against those very same consumer activists. And once again the Australian Government is threatening to drown free political debate in a sea of litigation and prosecution.

The Competition and Consumer Act currently exempts consumer and environment activists from its general ban on secondary boycotts. Colbeck wants to remove that exemption. The ACCC would then be able to take bodies like GetUp to court to stop their campaigns.

There's a technicality in here: we're talking about secondary boycotts, not primary boycotts.

A primary boycott is targeted directly at a company which has done something offensive. Don't like how a biscuit manufacturer operates, so you and your friends stop buying their biscuits? That's a primary boycott.

By contrast, a secondary boycott targets the biscuit company's suppliers and consumers. The aim is to punish the offending company by punishing those who the company relies upon.

The classic secondary boycott is the sympathy strike - where unions in other companies down tools in solidarity with aggrieved comrades. Sympathy strikes were endemic in the old heavily-regulated Australian labour market. Both major parties now largely agree that sympathy strikes ought not to be considered legally protected industrial relations action.

People get very agitated by secondary boycotts. You can understand why. They're indirect. They're often pretty unfair - secondary boycotts, particularly in the age of social media, can be poorly thought-through, arbitrary, and capricious.

If you've spent more than a few minutes on Twitter, then you've seen the madness of crowds.

But, as uncontrollable and impulsive as consumer campaigns can be, it would be entirely illiberal to try to suppress them by force of law.

Consumer boycotts - primary or secondary - are a completely legitimate way to express political views. Free markets aren't just a tool to bring about efficient exchange. They are a dynamic ecosystem of individual preferences about what we want to buy and from whom.

And sometimes those preferences involve ethical judgments about corporate values.

Companies know this. They know values sell. That's why we're subjected to flashy social responsibility marketing campaigns. That's why fair trade coffee exists. That's why British Petroleum is now "Beyond Petroleum" and its logo is a pretty green sun.

It's only fair that consumers are lawfully allowed to respond in kind. If that means unwelcome pressure on companies, well, such is capitalism. Consumer preferences can be tough to navigate. Messy as it is, political outrage is part of the push and pull of a free and open society.

I suggested above that consumer activists may have bought this partially on themselves. To stop the Competition and Consumer Act from being absurd on its face, its drafters carved out exemptions for 'nice' activists. But doing so leaves the law vulnerable to the charge, made by the Tasmanian Liberal MP Eric Hutchinson here, that there isn't a level playing field between companies and their activist opponents.

Once we have accepted that the regulatory state ought to control and supervise everything we do in the market, it's no great leap for that state to control our political expression.

The Coalition's boycott proposal demonstrates again that the distinction between economic freedom and free speech is not always great. Sometimes the way we spend our money is literally a form of speech. (I've argued this before. Take, for instance, the ban on David Hicks profiting from his memoir, or the O'Farrell government's crackdown on political donations.)

The Abbott Government says it wants to restore freedom of speech in Australia. It has promised to partially repeal Section 18C of the Racial Discrimination Act. This would be a good thing.

But if, at the same time, the new government imposes new restraints on how private civil society organisations can express their views, it will have done nothing to bring the cause of free speech forward.

Chris Berg is a Research Fellow with the Institute of Public Affairs. His most recent book is In Defence of Freedom of Speech: from Ancient Greece to Andrew Bolt. View his full profile here.