The U.S. Supreme Court hears arguments Tuesday in a case that pits the right to know against the right of free speech.

On one side are self-identified "crisis pregnancy centers" that seek to prevent abortions, and on the other side is the state of California, which enacted a law to ensure that these centers do not intentionally or unintentionally mislead the women who walk through their doors.

Supporters of the California law call the state's effort nothing more than seeking "truth in advertising."

But anti-abortion pregnancy centers see the law as unconstitutional, compelling speech that turns them into mouthpieces for a government message they disagree with.

Passions run high when it comes to abortion. Add the fact that most anti-abortion pregnancy centers have a firm Christian perspective, and you have quite a volatile mix.

Notice requirements for unlicensed and licensed centers

The case before the Supreme Court began in 2015 when California passed a law known as the FACT Act. (It stands for Freedom, Accountability, Comprehensive Care and Transparency.) The impetus was two-fold — first, allegations that pregnancy centers opposed to abortion were using deceptive practices; and second, concern that lower-income women, in particular, weren't aware of the free pregnancy-related services California provides, from pre-natal and delivery care to birth control and abortion.

The FACT Act requires unlicensed crisis pregnancy centers to post a sign or otherwise disclose to their clients in writing that the center is not a licensed medical facility and has no licensed medical provider who supervises the provision of services. The disclosure requirement extends to advertising, which anti-abortion pregnancy centers object to as an attempt to "drown out" their message.

But even the aggressively anti-abortion Trump administration has sided with California in arguing that this provision is constitutional.

The administration, however, opposes the second provision of the law dealing with licensed centers. It requires clinics that do not provide a full range of reproductive care, including services covered by Medicaid, to post a sign that says the state provides free or low cost access to pre-natal and delivery care, birth control, and other reproductive care, including abortion.

The sign is to include the phone number of the county social services office for referrals. But licensed centers do not have to post the notice in their advertising.

Protecting women from deception or trampling on the "pro-life" message?

As the state sees it, the provisions for licensed and unlicensed clinics are neutral public health measures.

"We're simply trying to make sure the recipient of health care information or advice understands exactly what he or she is entitled to in terms of services and that the information is accurate," said California Attorney General Xavier Becerra in defending the law.

That is not how the anti-abortion centers see it.

The law "is requiring a licensed center... that is pro-life and wants to help women choose life, point the way to an abortion," said lawyer Kristen Waggoner, who represents the anti-abortion pregnancy centers that are challenging the California law. That, she adds, "is not simply information."

As for unlicensed centers, she said, there is no need to disclose the lack of a medical license. "They're not doing anything that requires a license," she said, "so why would they need to say that?"

There are plenty of good reasons, replies Nancy Northup, president and CEO of the Center for Reproductive Rights.

"There has been an explosion of these fake health clinics that mislead women in ways that are very troubling and in some cases dangerous to their health," Northup said. "If these fake medical centers had on their front doors, 'We're pro-life centers. We're here to help you decide to continue your pregnancy,' there's nothing wrong with that, and that's fine. But what they're trying to do instead is lure women in on false pretenses."

In recent years, the number of pregnancy centers that counsel against abortion has dramatically increased. Today there are about 2,700 of them around the country, more than three times the number of clinics that provide abortions.

And just as some states provide taxpayer funds for abortions, 14 states directly fund anti-abortion pregnancy centers. From 2001 to 2006, the centers received an estimated $30 million in federal funding.

There is no data on how many of the 2,700 anti-abortion pregnancy centers are unlicensed. But unlicensed clinics offer pregnancy tests, limited ultrasounds, and, to an unskeptical eye, they can look very much like a licensed medical facility.

The personnel wear surgical scrubs or white coats and ask clients to fill out medical history questionnaires. Indeed, many clinics locate next to or across the street from a full service women's reproductive health center and some use similar sounding names.

Manipulating search engines

Do these anti-abortion pregnancy centers deliberately locate close to abortion clinics? "I sure hope so," said anti-abortion advocate Waggoner, "because women should have both options. And they shouldn't see only a provider that has a financial incentive to get them to abort a child." Waggoner is arguing in the Supreme Court on Tuesday on behalf of the National Institute of Family and Life Advocates, NIFLA, an umbrella group of anti-abortion pregnancy centers.

Some anti-abortion pregnancy center personnel are even more blunt.

Jacob Hall is director of services and client care at Care Net, an organization that supports crisis pregnancy centers. At a recent Care Net conference, he advised the centers on how to use search engines to identify key words for their marketing and websites, the object being to attract women searching online for an abortion clinic to an anti-abortion pregnancy center instead.

"I know 'abortion pill' is something people are searching," he said. "'Abortion clinic,' 'abortion clinic near me,' 'abortion cost,'" Hall said. "Fantastic key words if those phrases are on your website. If they're not, easy, just add them. Just say, 'we're here to talk to you about abortion, including abortion pills and abortion surgery.'"

At the same conference, Jana Pinson, director of a crisis pregnancy center in Texas, said she had great success with the term, "planning parenthood." Though her clinic opposes abortion, she changed her website tag to 'The Number One Source of Abortion Information in the Coastal Bend,' "because we are," she said.

Brian Fisher, of Human Coalition, another group that helps anti-abortion clinics, has also advocated using these tactics to attract women seeking an abortion in hopes of derailing their plans. This sort of marketing is necessary, he argued last year, because "the abortion-determined woman will not walk into a pregnancy center voluntarily."

Several women NPR contacted were infuriated by these tactics.

Annie Filkowski went to a clinic because it advertised free pregnancy tests. She spent hours there before learning she was not pregnant, and when she then asked a counselor to write her a birth control prescription or give her advice on which method to use, she said the counselor told her, "Birth control causes infertility and can give you cancer" and other "crazy" things.

Dartricia Walker said she went to a clinic for a pregnancy that she very much wanted. She mistakenly thought it was a medically licensed facility, and that the person who conducted the ultrasound was a nurse. Neither was true. She then had a miscarriage that a doctor later told her might have been avoided had she received adequate medical care.

"I was really upset that I was given the wrong date," Walker said, "because if I had known that I was due sooner, I would have gone sooner to an ob/gyn."

There are excellent clinics that oppose abortion, too. For an example of those, NIFLA, which is challenging the California law, referred us to "Informed Choices," a licensed clinic in Gilroy, CA, that has a staff of five, including two nurses, plus a volunteer ob/gyn who supervises medical procedures, and 20 other volunteers.

Christine Vatuone, the executive director, said that while the clinic does oppose abortion, and will not refer patients to an abortion provider, all patients are clearly told that they have three options: abortion, adoption and parenting — and that every room in the center has a sign with five promises: "that we will treat them with respect, that we will protect their privacy, that we will not pressure them, that we will support them, and that we will not lie to them."

Still there is room for confusion about the clinic. Google "pregnancy, Gilroy, CA," and the first three results are for Informed Choices, while the fourth is Planned Parenthood.

Google "Abortion, Gilroy, CA" and Informed Choices comes up too.

And "on advice of counsel," the clinic does not display the mandatory language in the California law advising patients that the state provides free access to a full range of care from pre-natal to abortion.

Many patients who seek out clinics that will support their pregnancy say they are thrilled with the counseling and material support clinics like Informed Choices provide, everything from food to baby clothes, diapers, car seats, and emotional support.

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