Canadian passport holders in recent weeks have shared troubling stories about their experiences at U.S. border checkpoints, spurring privacy and legal concerns about what travellers should expect.

The short answer is everything and anything, says Toronto-based immigration lawyer Heather Segal.

"The Trump order is going to be read as giving tacit approval to all sorts of things that may or may not be legal," Segal told CBC's Metro Morning, referring to the new executive order issued Tuesday.

"I think it's important for people to know what their rights are, so they don't have issues going into the United States and they can be clear."

Segal also notes that travellers in many cases are at the mercy of the border agents.

"They have full discretion," she said.

What's happening with Canadians at the border now?

Manpreet Kooner, left, pictured with her fiancé. Kooner, who was born in Canada and holds a Canadian passport, says she was turned away at the U.S. border and told she needed an immigrant visa. (Submitted by Manpreet Kooner)

Most recently Manpreet Kooner, a Canadian citizen, said she was told she needed an immigrant visa when she tried to enter the U.S.

Kooner's story is the latest in a string of similar accounts involving people facing unusual questions at the border. Fadwa Alaoui said she was asked about her religion and views of U.S. President Donald Trump before being turned away. Joseph Decunha and Sasha Dyck said they were refused entry into the U.S. in January when they planned to attend the women's march in Washington, D.C.

Do Canadians actually need a visa to travel to the U.S.?

Canadians do not need visas to travel to the U.S. Segal calls Kooner's case "bizarre," but she notes that it's likely Canadians are likely to experience more encounters like this in the future.

"There's a generic document that's used that prevents people from going to the United States if [U.S.] Immigration believes they need a visa," Segal explains. "Immigration uses this for Canadians even though Canadians do not require visas and the issue may not in fact be that they require a visa but it's this generic document that's very imprecise."

Do border agents have the right to ask about religion, political ties, etc.?

Yes, U.S. Customs and Border Patrol agents may ask any questions about your trip.

"They're entitled to ask all sorts of questions, including potentially your political affiliation. Your intention for traveling to the country certainly is a question that they almost invariably ask," Caily DiPuma, a lawyer with the B.C. Civil Liberties Association, told CBC's As It Happens.

DiPuma notes the questions must be posed without a discriminatory intent, given that the agency says they don't block entry on the basis of religion, race, ethnicity or sexual orientation.

What about my phone or computer — can I refuse to hand them over?

Border agents might ask to inspect your digital devices and you can refuse to hand them over, but you may face consequences. Alaoui was asked for the security code for her smartphone, which she handed over. Had she refused, she likely would have been refused entry in future attempts, DiPuma says.

"She could have declined to do so, but the result would have been that she would not have an opportunity to enter the country. And you know, as a matter of course, interactions with border guards are documented," DiPuma explained.

"They're documented on both the Canada and the U.S. side. So it's highly likely that she would have faced additional difficulties getting into the country if she did refuse to provide her electronic devices."

U.S. border agents are also authorized to seize your phone, should they deem it necessary. They can also make a copy of the data housed on the phone for analysis.

Is it common for phones to be searched?

It's still rare for U.S. border guards to search digital devices, according to a New York Times report that said 4,444 cellphones and 320 other electronic devices were inspected in 2015. This represent 0.0012 percent of the 383 million arrivals. In 2016, 23,000 searches were conducted.

I'm planning a trip to the U.S. What can I do to prepare?

If you're nervous about being turned back at the border, there are a few things you can do in advance, says Segal. Be prepared to show evidence that you're not planning on staying in the U.S. permanently. Have dates and times of business meetings or holiday tickets ready to show, she says.

Be prepared to answer the two standard questions travellers are routinely asked, what's the purpose of your visit and how long will your trip be.

Bring only what you need. The California-based Electronic Frontier Foundation, a digital rights advocacy group, suggests that travellers make a backup of the data on their devices and consider encryption methods for files you need to bring with you. Some travellers might also want to explore encrypting and storing their data in an online cloud service so they can access it when they arrive.

Is it easier to pass through customs at an airport or at a border checkpoint?

People trying to pass through customs at an airport in Canada may have an easier time than people trying to drive across the border, immigration lawyer Heather Segal advises. (Travis Golby/CBC)

Segal says that people trying to pass through pre-clearance customs at an airport in Canada may have an easier time walking away from the proceedings over people trying to drive across the border.

"When you cross at an airport you still have the right to leave at any point in time," she said. "They cannot detain you if you choose to leave. At a land point of entry, you don't have that right. So if you're worried about crossing and you're uncomfortable, it's better to cross at an airport."

I was turned away. What can I do now?

The U.S. Department of Homeland Security has an appeals process called the DHS Traveller Redress Inquiry Program, for people who experienced problems at the border. But ultimately, it's up to the discretion of the U.S. who they admit and who they block.

"It's not a right, it's a privilege," Segal says.

Why is this happening now?

The groundwork for stringent, at times puzzling, border interrogations was laid following the Sept. 11 attacks, says Segal. Border agents were given the right to search laptops in 2008.

"[The U.S.] became very strict about a lot of immigration issues, and security was primary," she said. "And the message to the folks at the border is, you can err on the side of denial and that's OK. And so things that may not be right or legal can happen at a border where the border officers feel … that they have the right to do these things because the message from the top security is everything is justifiable under security."