AILSA CHANG, HOST: Comedian Ben Palmer specializes in pranks. He once created a website to gather complaints about Cracker Barrel changing its logo. Recently, he had a more controversial idea for a prank to set up a fake tip line for people to call in and report undocumented immigrants. Now, he wasn't sure he would get that many calls, but it turns out he got hundreds. NPR's Jasmine Garsd reports.