The New Hampshire blogger fought back, asking a judge to quash the subpoena. This week, a federal district court agreed with Seidel and not only granted her request, but also ruled that the lawyer who attempted to subpoena Seidel must defend himself against potential sanctions for issuing the "burdensome" document.

The ruling is seen boosting the ability of citizen journalists and other online publishers to stand up to critics who try to silence them by issuing subpoenas or engaging in other legal maneuvers. "It's very good news for individuals who blog on controversial topics," said David Ardia, director of Harvard's Citizen Media Law Project. Ardia added that bloggers faced with subpoenas often feel compelled to either turn over the information or "willingly shut down their criticism in an effort to avoid a legal threat."

The case stemmed from a post Seidel wrote on March 24. In that post, she wrote about a recent legal decision regarding thimerosal in vaccines, which some people suspect causes autism and other disorders. She also blogged about Clifford Shoemaker, a prominent lawyer for plaintiffs in cases involving injuries from vaccines, and how much he was awarded in attorney's fees and costs.

Seidel alleged that shortly after the post went live, she received a subpoena from Shoemaker, who is currently representing Lisa and Seth Sykes in a lawsuit in federal court in Virginia against Bayer Corporation. The Sykes allege that their son developed autism as a result of exposure in utero to mercury.

The broad subpoena demanded a host of information from Seidel, including tax returns, LexisNexis records and copies of communications with a wide range of groups or individuals ranging from the federal government to editorial boards to journals.

She argued that she was entitled to the same privilege as traditional journalists in her state, where judges have held that reporters have protection for newsgathering activities.

"Although I am unaffiliated with a traditional news organization," she wrote, "I am a de facto citizen-journalist regularly engaged in the public dissemination of news and information, and the promotion of discourse and advocacy regarding issues of national importance."

The court didn't give any reasons for quashing the subpoena, but ordered Shoemaker to show why he shouldn't be sanctioned for violating a rule to avoid "burdensome subpoenas."