The US is tolerating Israel’s mistreatment of US citizens of Palestinian origin, Arab-American advocates are saying. Israeli authorities have recently refused entry to several Palestinians with US passports, including an outspoken activist.

When Nerdeen Kiswani tried to cross into the West Bank at the Allenby Bridge crossing, she was interrogated for 15 hours, and then denied entry based on her “hostile behavior towards Israel.”

Kiswani, a student at CUNY Staten Island and Hunter College in New York City, has crossed without much trouble in 2013 and 2014. Last month, however, Israeli border guards interrogated her about her political activism, including the involvement with Students for Justice in Palestine (SJP) and the Boycott, Divestment and Sanctions (BDS) movement. Her US passport meant nothing to the Israelis, Kiswani told RT.

“It doesn’t matter to them what passport Palestinians hold,” she said.

“I think simply being a Palestinian in itself is a threat to Israel, because it challenges their narrative,” said Kiswani, who believes she was singled out because of her outspoken activism.

Palestinians not involved in activism have faced similar treatment, however. George Khoury, 70, was a deacon from San Francisco on a pilgrimage, while Habib Joudeh, 62, was a Brooklyn pharmacist headed for a family wedding. Both flew into Ben Gurion international airport last month, and had to fly back at their own expense, according to James Zogby, president of the Arab American Institute.

Writing in The Hill, Zogby blasted the US government’s position on the issue, which he said amounted to quiet consent. The State Department’s travel advisory page for Israel simply notes that “Israeli authorities consider anyone who has parents or grandparents who were born or lived in the West Bank or Gaza to have a claim to a [Palestinian Authority] ID.”

“Israel cannot be allowed to disregard the citizenship rights of Americans or to unilaterally define persons of Arab descent as second-class American citizens,” Zogby wrote.

Jim Zogby in @thehill "it is a question of whether or not our govt will guarantee #ArabAmericans equal protection" http://t.co/dkd3UMru9x — Kristin McCarthy (@krstnmccrthy) August 24, 2015

One of the things that rattled Kiswani during her interrogation was the realization that the Israeli security agents seemed to have a detailed file on her, the SJP, and the BDS activities. “I knew they knew about everything I was involved in, and I was really terrified,” she said in a recent interview with the Palestinian advocacy website the Electronic Intifada.

According to revelations in the Israeli newspaper Ha’aretz, in 2010 the Israeli military intelligence set up the Delegitimization Department, a special outfit charged with monitoring BDS activists around the world.

Launched by a coalition of Palestinian groups in 2005, the BDS movement has led to an academic boycott of Israel at many university campuses, numerous artists cancelling performances in Israel, and a number of companies abandoning their business investments in the country.

NUS in upheaval after president breaks Israel boycott by accepting Coca-Cola sponsorship http://t.co/cP5JwSLkDDpic.twitter.com/PqL9zBHoSj — RT UK (@RTUKnews) July 21, 2015

Student organizations in particular are actively backing BDS. Last month, the National Union of Students in the UK censured its president for accepting a sponsorship from Coca-Cola, a target of the BDS movement for operating a bottling plant in Israeli-held West Bank.

While the exact impact of BDS on the Israeli economy has been difficult to pinpoint, a recent estimate by the RAND Corporation put the potential damage at $47 billion if the campaign continues for another decade.