Why is Snyder v. Phelps considered a Landmark Decision?

Snyder v. Phelps is considered a landmark decision due to the fact of how much of an uproar it caused and continues to cause throughout the United States. Not only are people still angry about the decision mad, but people are also emotionally hurt. Families are unable to prevent the Westboro Church from protesting at their loved one's funerals. The decision shocked many people in the country.