The precedent for the laws was set in Frisby v. Shultz, a 1988 U.S. Supreme Court decision that upheld a Brookfield, Wis., ordinance banning picketing in front of a residence. The 6-3 decision, which stemmed from a challenge of the law by anti-abortion protesters, said that because the picketing was "speech directed primarily at those who are presumptively unwilling to receive it," the city had a substantial and justifiable interest in banning it.