The Court found that the group picketed and engaged in free speech in compliance with local rules and that its choice of picketing didn't disrupt the funerals themselves, but more importantly - that the US has chosen to protect hurtful speech on public issues to ensure that public debate is not stifled.
The Westboro picketers carried signs that were largely the same at all three locations.They stated, for instance: “God Hates the USA/Thank God for 9/11,” “America is Doomed,” “Don’t Pray for the USA,” “Thank God for IEDs,” “Thank God for Dead Soldiers,” “Pope in Hell,” “Priests Rape Boys,” “God Hates Fags,”“You’re Going to Hell,” and “God Hates You.”
The church had notified the authorities in advance of its intent to picket at the time of the funeral, and the picket-ers complied with police instructions in staging their demonstration. The picketing took place within a 10- by25-foot plot of public land adjacent to a public street,behind a temporary fence. App. to Brief for Appellantsin No. 08–1026 (CA4), pp. 2282–2285 (hereinafter App.).That plot was approximately 1,000 feet from the church where the funeral was held. Several buildings separated the picket site from the church.
The First Amendment isn't about protecting favorable speech, but protecting political speech that isn't liked, so while courts have held that even protected speech is not equally permissible in all places at all times (Cornelius v. NAACP Legal Defense Fund), the group was conforming to local rules on where and how to picket. The group's members had the right to be where they were and the right to engage in speech as they did.
The Court ruled that the outcome is limited to the particular facts before the Court, so the precedent set here is limited.