About 10 days ago, a fish merchant in Jerusalem's Mahane Yehuda outdoor market noticed a young man with sidelocks and a skullcap trying to determine which of the stalls employ Arabs. The merchant, Saleh, called the police, who detained the man for questioning on suspicion that he was planning a terror attack.

But the interrogation revealed that Meir Ettinger, 19, had a completely different goal in mind. Ettinger, a resident of the West Bank settlement of Yitzhar and a grandson of the late Rabbi Meir Kahane, said he was investigating on behalf of a project called Hebrew Labor, whose goal is "to warn the public" against buying from businesses that employ Arabs.

Open gallery view Saleh at work in a fish stall in Jerusalem’s Mahane Yehuda market. Credit: Emil Salman

Ettinger was released and ordered to keep away from Mahane Yehuda for two weeks. But last Thursday night, police detained four other young men from Yitzhar who were on the same mission.

Conversations with right-wing activists this week revealed that Ettinger and his comrades have been working on this project for several weeks now. Their goal is to map all of the businesses in Jerusalem that use Arab labor. They began in the northern neighborhoods of Pisgat Ze'ev and Neveh Yaakov, then moved to the western neighborhoods of Kiryat Moshe and Givat Shaul, and are now working on the downtown area, which includes Mahane Yehuda.

"They came to my boss and asked him if he has Arabs working for him," related Yaakov Azaria, an electrician from Pisgat Ze'ev. "He said no, but I know they also went to others and asked them."

About 20 people are working on the mapping project. Most are Yitzhar residents who were recently served with administrative orders requiring them to stay out of the West Bank, for fear that they might carry out attacks on Palestinians or soldiers, and are therefore living temporarily in Jerusalem. Their goal is to prevent people from patronizing businesses that employ Arabs.

"A booklet with a list of places that employ Arabs will be published soon," said Moshe Ben Zikri, an extreme right-wing activist from Jerusalem. "That will be followed by hanging up posters and signs with these lists in the streets - just so that the public will know and be cautious."

The modus operandi is simple: If it isn't clear that a store does or doesn't employ Arabs, the activists simply walk in and ask the owner. Police found a list of several dozen businesses in Ettinger's pocket, each marked with an X if it employed Arab workers or a checkmark if it did not.

The Hebrew Labor project is not one of a kind: In January, for instance, a right-wing group called Lehava - For the Prevention of Assimilation in the Holy Land launched a campaign to give "kashrut certificates" to businesses that don't employ Arabs. Benzion Gopstein, one of the leaders of Lehava, said this new campaign was unrelated, but motivated by the same goal.

"I don't understand what the problem is here," he said. "All in all, this is just a service to the public that isn't interested in buying from businesses with Arabs."