This summer, a group called the Center for Medical Progress began to release a series of videos from an undercover “investigation” which it claimed showed that Planned Parenthood “sells aborted baby parts” for profit.

Since then, those claims have been roundly debunked, but the stir created by CMP’s videos has led to votes on defunding Planned Parenthood in the House and Senate and in several states, multiple House hearings (including one happening right now) and the threat of a government shutdown, and even contributed to the resignation of the speaker of the House.

Although little was known at first about who the Center for Medical Progress was, researchers and journalists quickly traced its ties to a number of radical anti-choice groups, and especially to Operation Rescue, which has existed for decades on the radical fringe of the anti-choice movement.

In a new report released today, People For the American Way explores the ties between CMP and its founder, David Daleiden, and Operation Rescue, placing Daleiden’s project in the history of the “direct action” anti-choice movement’s attempts to harass and intimidate abortion providers and patients.

In a radio interview first reported in the PFAW report, Operation Rescue’s second-in-command, Cheryl Sullenger, who spent time in federal prison in the 1980s for attempting to bomb an abortion clinic, explained that Daleiden approached her organization because he “shared our vision” for bringing “an end to the abortion industry in America” through attacking Planned Parenthood.

The “direct action” movement that Operation Rescue and CMP represent originated with dissidents from the National Right to Life Committee, which after the Supreme Court’s decision in Roe v. Wade was the main organization working to overturn the decision and outlaw abortion through legislation. Early “direct action” protesters abandoned this legislative strategy and instead focuses on attacking legal abortion at its source, harassing abortion providers and patients and sometimes physically preventing women from entering abortion clinics in what became known as “rescue” missions.

As part of this strategy, Operation Rescue now advises activists to use a wide range of methods, including covert ones such as the “sting” operation Daleiden carried out, to gather information on abortion providers (and sometimes patients) in order to harass them at their homes and workplaces or to make their clinics expensive to operate.

One strategy later perfected by Mark Crutcher, who runs a group called Life Dynamics, used sham “investigations” to infiltrate and unnerve abortion providers. One of Crutcher’s investigations attacked the legal practice of fetal tissue donation for medical research; Daleiden has admitted that Crutcher gave him the idea for CMP’s project. The purpose of Crutcher’s investigations was not to shed light on hidden truths, but instead to intimidate abortion providers in order to stop them from offering their services, with the goal of building Crutcher once called “an America where abortion may indeed be perfectly legal, but no one can get one.”

Although Daleiden calls himself an “investigative journalist,” he actually comes out of this tradition of intimidation and harassment disguised as investigation.

PFAW’s full report, “Operation Rescue’s Big Break: How an Organization Rooted in the Radical Fringes of the Anti-Choice Movement Is Threatening to Shut Down the Government,” is available here.