The young, sandy-haired boy wears a self-satisfied expression. His small hand is clenched as if he is in the middle of a triumphant fist pump. By now, Laney Griner is used to seeing the photo she took of her son in 2007 when he was 11 months old splashed across the Internet or featured in various advertisements. The child’s name is Sam, but for years the world has known him as the popular Internet meme, “Success Kid.” Last week, Griner discovered her son’s copyrighted image in the last place she ever expected to find it: a campaign fundraising ad for...