It’s been a long, winding journey for the shield law. But the bill, which would provide journalists with some protection from being forced to testify in federal cases, has never appeared closer to becoming a reality than it does today.

On March 31, the House of Representatives passed a version of the Free Flow of Information Act—the shield law’s formal name—by a voice vote. Backers cleared an unexpected hurdle in late October when the White House and the bill’s prime sponsors on the Senate Judiciary Committee reached a compromise on just how robust the shield’s protections will be.

There is still some distance to go, and one clear sticking point along the way will be just who the bill should cover. It’s a tough, high-stakes question—those who end up on the wrong side of the line will get none of the bill’s protections.

For some people receiving subpoenas, that’s as it should be—not everyone is a journalist, and those that aren’t shouldn’t get protection.

But defining who’s in and who’s out is a tricky matter. The boundaries of state-level shield laws and court decisions recognizing some version of a reporters’ privilege have often been tested by everyday citizens and borderline cases who are called to testify and find it convenient to claim that they were acting as journalists when they came into information that a prosecutor or civil litigant wants to air in court. (One prominent example, decided in the Court of Appeals for the Third Circuit in 1998, ruled that a pro-wrestling color-commentator who was occasionally involved in plotlines was not entitled to the privilege.)

That prospect that non-journalists could abuse the privilege has raised concern among legislators, according to Paul Boyle, senior vice president for public policy at the Newspaper Association of America, and a leader in the journalism industry’s struggle to bring a formal shield into law.

“One senator who was concerned about the definition of who was a journalist said ‘We want to cover as many people as possible without covering all the people who shouldn’t be covered.’ Well, how do you draft that language to meet those objectives?” asked Boyle, with a chuckle.

Throughout the past several years’ effort for a federal shield bill—spurred by the high-profile cases of Matt Cooper, Judith Miller, Josh Wolf, Mark Fainaru-Wada, and Lance Williams—the definition of a covered person has shifted with almost every draft. At heart, there are essentially two approaches to the question. Are journalists best defined by the act of reporting (what’s known as a functional definition), or by how they are employed (a status-based definition)?

The most restrictive status-based definitions under consideration could require protectees to be employed by traditional news organizations, a restriction which would leave book authors, freelancers, student journalists, and independent bloggers—maybe even journalists working for online-only outlets—without any protection against being forced to testify in court.

The already-passed House bill adopts a financially-dependent status definition, requiring that anyone seeking the shelter of the law practice journalism for “a substantial portion of the person’s livelihood or for substantial financial gain.”

That isn’t how journalists would like the question answered.

“We have never been behind any language that deals with financial gain,” says Kevin Smith, president of the Society of Professional Journalists. “We’re just not behind that. Never have been.”

High among Smith’s concerns is how student journalists would fare, given that they comprise a large proportion of SPJ’s membership. In fact, Laurie Babinski, a legal advisor to the Society, says they wanted the word “livelihood” included in the House’s definition, in hopes that if the language made its way into law, a judge would be sympathetic to a student journalist who argued something like “’This is part of my training for my future profession—part of my livelihood.’”

Federal courts would of course inevitably be forced to interpret the linguistic vagaries of any bill. But the shield bill’s journalism community backers have always preferred a functional definition with broader reach, both for flexibility and because many different kinds of journalists, working on many platforms and for outlets with various business models, comprise the membership of the seventy-plus organizations involved with the effort.

“I can’t stand up and support legislation that would provide the proper protection that a shield bill would for 80 percent of my membership and sell my other 20 percent down the road,” says Smith, a professor of journalism at Fairmont State University in West Virginia.

And many are mindful that, as technological and financial issues upend the way journalism has been done, a functional definition stands the best chance of meeting the test of time.

Clint Hendler is the managing editor of Mother Jones, and a former deputy editor of CJR.