(NBC NEWS) A majority of Supreme Court justices appeared skeptical Wednesday of a Massachusetts law that establishes a 35-foot buffer zone to prevent protests outside clinics that provide abortions — a restriction the protesters say violates the First Amendment.

In an oral argument, some justices said they were concerned that the law restricts speech in a way that is not neutral among viewpoints: Clinic workers can talk to patients inside the buffer, while those who object to abortion cannot.

The justices also appeared to worry that the 35-foot zone is too big, and some voiced general concern with the concept of restricting speech on a public sidewalk.

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