He stares hard at the camera, his clenched fist full of sand. The mother of the boy in this ubiquitous meme sent a cease-and-desist letter to Representative Steve King on Monday, demanding that the congressman remove her son’s copyrighted photo from websites and campaign materials.

The mother, Laney Griner, sent the letter through her lawyer on Monday after discovering that the picture of her son, Sam, had appeared in an ad for Mr. King, a Republican from Iowa with a long history of making racist remarks.

In the original photo, an 11-month-old Sam is on a beach, looking at the camera with an expression of intense concentration and his fist raised. As is the way with memes, the image has been repurposed and shared all over the internet, used by people to express relish over a hard-won victory or demonstrate an iron determination to bounce back.

It is a baby photo that says, “You haven’t seen the last of me.”

Last week, Sam appeared on the King for Congress Facebook page, in an ad that superimposed him over an image of Congress, with the text “Fund our memes!!!”