As human trafficking gains national momentum as an issue that must be dealt with harshly in the courts, some worry that laws may over-reach.

Scenario: Police discover a human-trafficking ring. Fifteen people are charged, including the men who physically held the young women captive, the driver of the car who took the victims to clients, and the person who created the advertisements used to sell them.

Is each person equally liable for the crime? Does it matter how much each knew? What was each person's intent?

As efforts to combat human trafficking in the United States gain momentum, some legal experts say questions like these must be asked as lawmakers draft legislation that could unintentionally lead to wrongful convictions and unfair stigmatization.

Supporters of the laws, however, say strong legislation is critical to fighting the problem. They say that like drug trafficking, human trafficking can involve many players working toward a criminal goal.

"We are seeing more human-trafficking indictments coming down, and we're seeing more instances of the government's grasp expanding to include marginal players," said Ryan Blanch, a federal criminal attorney and managing partner of the Blanch Law Firm, which has handled several human-trafficking cases.

Human trafficking is defined by the State Department as the recruitment, transportation or harboring of people by means of deception or coercion. Victims, often mentally and physically abused, can be forced into prostitution, unfair working conditions or other exploitative situations.

In some cases, "marginal players" are people running legitimate businesses like car services and advertising companies who may have unknowingly helped traffickers and find themselves charged as equal participants in cases, Blanch said. He added that those charged may not even know the traffickers but are charged as if they forced victims into the actions themselves.

Advocates working to end human trafficking argue that asking how much everyone involved in a trafficking scheme knows is key to understanding how such enterprises work and who should be charged.

"There are usually multiple players involved in the bigger cases," said Mary Ellison, director of policy for Polaris Project, a non-profit group that runs the national human-trafficking hotline. "It's like any other type of organized crime. There are a whole slew of people who are involved in the crime."

Meanwhile, there's no evidence that any laws are being applied unjustly, as the number of convictions is far less than the number of cases nationwide, she said. For Ellison, the past few years illustrate that politicians, law enforcement officials, and prosecutors are just starting to understand how trafficking affects the United States.

Evidence for that can be seen across the country. New Jersey Gov. Chris Christie, a Republican, will soon consider whether to sign a bill to toughen human-trafficking laws in his state ahead of the 2014 Super Bowl, the kind of event that historically prompts an increase in sex trafficking. A bill in Maryland aims to seize the property of people charged with the crime. And in Nevada, lawmakers want to provide an avenue for victims to sue their captors in civil court.

Despite the rising number of trafficking laws and convictions, Ellison says that the burden to prove someone is a trafficker is high, and prosecutors in every case must prove that the person charged knew about the trafficking and intended to further it.

Still, Blanch argues trafficking charges at times attempt to wrongfully limit the free speech of advertisers and make legitimate businesses responsible for investigating what their clients are doing with their services.

Steven Benjamin, president of the National Association of Criminal Defense Lawyers, said being charged with human trafficking can ruin someone's life even if they are acquitted. While criminal records can be cleared, the Internet continues to connect someone to trafficking.

As a result, lawmakers must be as specific as possible in crafting legislation and avoid hastily passing bills aimed at trafficking, because it's the current crime getting a lot of attention, he said.

"If lawmakers attempt to criminalize certain actions associated with human trafficking, the risk is that they will criminalize socially appropriate, if not desirable, activities in the process," Benjamin says. "Too often lawmakers will pass legislation that addresses a problem without paying attention to the unintended consequences."

Maryland State Delegate Kathleen Dumais, a Democrat, heard such arguments for more than three years as she unsuccessfully tried to get a trafficking asset-forfeiture bill past her state's House Judiciary Committee.

Several defense attorneys on the committee were uncomfortable with seizing assets of suspects and successfully blocked the bill from coming up to a vote.

Last week, however, the bill, which would allow authorities to seize the assets of suspected traffickers and confiscate them if they are convicted, made it out of the committee after some changes.

It was passed unanimously by the House on Monday. It will now head to the Maryland State Senate next week, Dumais said.

"Sometimes defense lawyers exaggerate things too much," she said. "It's really difficult to prosecute traffickers without better tools and statutes."

Contributing: The Associated Press