The 'Stop the 30 billion' coalition
The billboard is one of ten being put up in New Mexico by an Albuquerque-based grassroots org (the Coalition to Stop $30 Billion to Israel).
The group looks to be multicultural, and led by two Jews, Lori Rudolph and Rich Forer. Forer says that he is a former member of the American Israel Public Affairs Committee (AIPAC) who has been shaken from ideological slumbers in the last couple of years by the Israeli New Historians. He has learned that Jewish schoolchildren are "grossly misinformed" about the conflict and are taught to demonize Palestinians. Gaza was a "monstrous act of inhumanity," he continues, and Israel must act sincerely to restore the dignity to both peoples.
Unfortunately, Phil's link to their press release doesn't work, but here's their website.