(AP) — A commission behind a memorial for teenage lynching victim Emmett Till in Mississippi was forced to get a new sign with a glass bulletproof front and add cameras and alarms after previous markers were riddled with bullet holes.

Itís one of numerous monuments to U.S. civil rights figures or events around the country that have been attacked by vandals through the years, forcing organizations and elected officials to spend hundreds of thousands of dollars to repair or replace the monuments and equip them with surveillance. There’s no movement to pass federal protections for such memorials, and advocates of the sites say their only recourse has been to rely on local and state vandalism and hate crime laws to prosecute suspects.

“It happens so much that I canít get angry because Iím not surprised,” said Maria Varela, a Mississippi civil rights organizer and photographer with a Student Nonviolent Coordinating Committee in the 1960s. “But this tells me the people who are doing this are still so scared.”

The need for protection for such memorials came into focus again this month after security cameras captured white nationalists trying to film in front of the new sign that describes how the body of Till, a black 14-year-old from Chicago, was pulled from the Tallahatchie River in Mississippi.