Ismail Ajjawi, a 17-year-old Palestinian student who was refused entry to the US last week when he arrived at Boston, was allowed to enter the country on Monday and was at Harvard in time for the beginning of classes. However, rights advocates warn that his story is part of a worrying trend.

Ajjawi, who was on a scholarship from Amideast, landed at Logan International Airport in Boston on August 23 and was turned back after being detained for eight hours. After interrogating Ajjawi and searching his phone and computer, US immigration officials revoked his visa and sent him home to Lebanon. Why?

According to a statement by Ajjawi, an immigration officer claimed she “found people posting political points of view that oppose the US,” though she discovered nothing Ajjawi had posted himself. Despite his protests that he had nothing to do with the Facebook posts, Ajjawi was found "inadmissible" to the US.

The episode prompted a furor among free speech activists and became a lightning rod for university officials. Amideast, an American nonprofit cultural exchange and education program founded in 1951, said the the public outcry over the case finally helped Ajjawi regain his visa.

Ajjawi, a Palestinian refugee had attended United Nations schools in the refugee camps of Lebanon, with dreams of becoming a doctor.

“We express our gratitude to the many voices in the media and the public at large, both in the United States and abroad, who recognized the injustice of what happened to Ismail and voiced their concerns in traditional media and on social media,” Amideast said in a statement.

Unexpected denials and long delays have become common for international students and scholars seeking US visas.

“Since May, the obstacles facing individuals ensnared in the nation’s visa and immigration process have only grown,” Harvard University Lawrence Bacow told “The New York Times.”

“Various international students and scholars eager to establish lives here on our campus find themselves the subject of scrutiny and suspicion in the name of national security, and they are reconsidering the value of joining our community in the face of disruptions and delays,” he added.

Sarah McLaughlin, director of targeted advocacy at the Foundation for Individual Rights in Education, said the group is alarmed by “the numerous recent accusations that US immigration officials are denying visas on the basis of political viewpoints.”

In June, the US Department of State said nearly all applicants for US visas would have to submit their social media details under newly adopted rules.

It said travellers would have to submit social media names and five years' worth of email addresses and phone numbers as part of the Trump administration’s extreme vetting policy towards visitors. 

President Donald Trump’s administration first proposed the rules in March 2018. Officials at the time estimated that the new regulations would affect 14.7 million people annually including foreign students.

Certain diplomatic and official visa applicants are exempt from the stringent new measures.