I spent so much time on picket lines as a kid that when I thought my dad’s rules were too strict, I would run to build a sign on a stick and try to talk the neighbor kids into marching around the house with me. I learned early on the power of a picket to protest unfair treatment.

That right is more important today than ever. As our economy has shifted toward a more contingent workforce, companies are increasingly hiring workers as part-time or temporary, or labeling them as independent contractors. This leaves workers more vulnerable to abuse while also shielding companies from accountability. When warehouse workers unpacking Walmart goods in a Walmart-owned warehouse were cheated out of their wages, the retail giant responded that those workers were hired through a temporary agency and are not the company’s responsibility.

These kinds of working conditions make it all the more important that workers be able to share their stories with the public. Consumers have the right to know about the kinds of labor practices they are supporting when they shop at a particular store. In this economy, where workers have so little bargaining power, the ability to picket an employer to expose unfair conditions is more important than ever.

That’s what makes the recent California Supreme Court decision in Ralphs Grocery Co. v. UFCW Local 8 so important. The court upheld two provisions of California law that protect the right of workers to picket. The Moscone Act protects peaceful picketing and communicating about the facts of a labor dispute on “any public street or any place where any person or persons may lawfully be.” Labor Code Section 1138.1 restricts injunctive relief to stop picketing unless a company can show substantial and irreparable injury, the commission of unlawful acts and several other factors. Ralphs sought to invalidate those state statutes, which would have silenced California workers from such peaceful protest.

In upholding California law, the court maintained a critical protection for working people. What is at stake here is far more than where in a shopping center picketers are allowed to stand. The picket line was—and still is—an essential tool in building the American middle class. Workers standing together, making their case in the court of public opinion, helped bring about the eight-hour day, the weekend, prevailing wage, anti-discrimination laws and so many other protections. It also helped working people win wages and benefits that allowed them to buy homes, send their children to college and give back to their community through taxes, service and time.

In essence, the picket sign has enabled generations of working people to achieve the American Dream. Given the economy we face today, it’s time for the next generation to start making signs and marching to demand those same opportunities.

“Why Picket Lines Matter,” by Caitlin Vega, originally appeared on the California Labor Federation’s blog Labor’s Edge. You can also view it on AFL-CIO NOW, posted on January 7, 2013.