The AP documents several cases in which travelers were refused entry if the search was refused or when officers didn't like what they found.

Diana Butto, a former legal adviser to the Palestinian Authority and a fellow at the Harvard Kennedy School of Government, said the policy of email checks, once used sporadically, appears to have become more widespread over the past year.

Butto said she has led three tour groups to the region over the past year, and in each case, at least one member of the group was asked to open their email. She said Muslims, Arabs and Indians were typically targeted, and in most cases, were denied entry.

Butto said agents typically want to see people's itineraries, articles they have written or Facebook status updates.

The problem is there's no way to honestly say you're coming to visit the West Bank without falling into some type of security trap, she said. Either you lie and risk being caught in a lie, or you tell the truth ... and it's not clear whether you'll be allowed in.

Tamari, who is from St. Louis, said she arrived in Israel on May 21 to participate in an interfaith conference. She described herself as a Quaker peace activist and acknowledged taking part in campaigns calling for boycotts and divestment from Israel.

Given her activism, Tamari said she expected some security delays. But she was caught off guard by the order to open her email account. She said the agents discovered her address while rifling through her personal papers.

That's when they turned their (computer) screens around to me and said, 'Log in, she said. When she refused, an interrogator said, 'Well you must be a terrorist. You are hiding something.'

Tamari said she was searched, placed in a holding cell and flown back to the U.S. the following day. The idea that somebody my age, a Quaker, on a peace delegation with folks from the U.S., would be denied entry — that never crossed my mind, she said.

Najwa Doughman, a 25-year-old Palestinian American from New York City, said she underwent a similar experience when she arrived for a one-week vacation on May 26.

A female interrogator ordered Doughman to open her Gmail account, threatening she would be deported if she didn't.

She typed in gmail.com and she turned the keyboard toward me and said, 'Log in. Log in now,' Doughman recounted. I asked, 'Is this legal?' She said, 'Log in.'

She said the agent searched for keywords like West Bank and Palestine and made fun of a chat in which Doughman talked of reading graffiti on Israel's West Bank separation barrier.