This colorful set of postcards might seem at first glance to be cheery souvenirs of towns and cities across America. Until you clock the names and look closer. 

Marking places such as Columbine, Newtown, Charleston and Parkland, they mark the locations of the deadliest mass shootings in U.S. history. A closer look at the the lettering on the cards reveals that they depict the chilling events that look place in that location.

The so-called "Shamecards" were created by MullenLowe for Change the Ref, the nonprofit dedicated to changing gun laws founded by Manny and Patricia Oliver, the parents of Parkland shooting victim Joaquin Oliver. (The agency's previous work for Change the Ref has included a campaign that brought Joaquin Oliver back to life using deepfake technology.)

Anyone can download one of the 50 digital cards (one for every state) from the website, and the idea is to flood the inboxes and mailboxes of members of Congress with demands for gun reforms. The postcards were illustrated by 30 artists from 25 countries across the world, and each tells the story of a mass shooting through an artist’s eyes, with a short description of each shooting on the opposite side.

In addition to the website and virtual postcards, a Shamecards mural will be on display in Parkland, Florida, with pop-up postcard stands in Los Angeles, Houston, New York and Seattle.

"America is known for mass shootings that happen over and over and over again. It’s time to turn this shameful reputation to a message of bravery, vindication and common sense,” said Manny Oliver in a statement. “Shamecards were created to embolden lawmakers who wouldn’t budge on gun control to stand up to the NRA and to challenge the representatives and senators who promised us they were on our side, to keep their promise.”