Residents of the United States who aren’t citizens ― and even some who are ― have become increasingly worried about traveling abroad under the Trump administration.

The number of enforcement actions carried out by Customs and Border Protection so far this year is lower than prior years, according to CBP statistics posted online. But disturbing reports of people being shackled, detained and threatened with deportation, some of whom have permanent residency and some without due process, have raised global concern.

Several countries, including Canada, Germany and the United Kingdom, have issued travel advisories for the U.S., with warnings of potential detention, arrest or denied entry at U.S. border points.

U.S. colleges also have advised international students against leaving the country due to the risk of deportation when they try to return. Secretary of State Marco Rubio estimated Thursday that at least 300 foreign students have had their visas revoked in relation to their alleged involvement in political protests.

“They’re sensational cases and they should be,” immigration attorney Richard Herman with Herman Legal Group told HuffPost of such reported instances, which include people being imprisoned in detention centers for weeks and pressured to relinquish their green cards by border guards. “I think the administration is trying to make an example out of them.”

HuffPost spoke with three immigration attorneys about the risks of traveling right now as a non-U.S. citizen. Here’s their advice on what to do and what not to do.

What’s Happening Right Now?

Trump terminated past catch-and-release policies upon taking office, with U.S. border agents instructed to instead detain anyone found violating immigration laws and hold them until they are removed from the U.S. The goal is to not only prevent illegal entry but to deter it, according to the White House.

This has resulted in people being detained for hours to weeks, if not indefinitely, while awaiting court hearings. Some permanent residents, or so-called green card holders, also have been threatened with deportation for political activism and past nonviolent offenses, including DUI, according to their loved ones.

“Understand that when they go in detention, they’re not getting out. They’re sitting there and they’re being pushed out of the country,” said attorney Robert Sichta with the Council on American-Islamic Relations’ Florida chapter.

The Trump administration is expected to unveil a travel ban targeting as many as 43 countries in the coming days. The ban, a draft of which was obtained by The New York Times, would flatly bar citizens from 11 countries from entering the U.S.

U.S. visa holders with passports from any of those countries could consequently be denied reentry if they are out of the U.S. when the travel ban goes into effect, warned Sichta.

What Travelers Could Expect At Checkpoints

Travelers arriving through border security may be taken in for secondary questioning if officers have any uncertainty about the individual. This questioning could last minutes to hours.

Non-U.S. citizen do not have the right to an attorney while being questioned about their immigration status at the border, though attorney David Nachman with the Nachman Phulwani Zimovcak Law Group in New Jersey, told HuffPost that there have been instances where an officer allowed his client to call him for help.

Phones, electronics and any other belongings may be searched and even confiscated. Though border control can’t stop Americans from reentering the U.S., their electronics can be searched and confiscated, Herman said.

What Could Possibly Go Wrong?

A traveler could have a spotless record and all the paperwork needed for reentry, but the final say comes down to the border officer conducting the review.

That officer could misinterpret information found on a traveler’s phone, including in photos, social media posts, emails or text messages. Such information could be discussions about future work plans or political protests, whether the information is about the individual or not, Nachman said.

“We can’t get into the heads of what these officers are thinking,” he said. “They are allowed to use discretion, or they’re allowed to interpret whatever the policy was the way they would interpret it.”

This can result in mistakes, especially if the border officer is not properly educated on the rules, which both Nachman and Herman said they have experienced.

“While they do deserve a great deal of respect because our nation’s security is first and foremost, you have to understand that they are not receiving the salary levels where they are going to go home and take the books and really learn the rules, so they’re really flying by the seat of their pants,” Nachman said.

He recalled one recent incident where a client of his returning to the U.S. from Dubai was stopped and told that she didn’t have the correct paperwork. The officer fortunately allowed her to call his cellphone.

“The officer started telling me what was missing, and I said to the officer, I hate to tell you, but the stuff you’re asking her, she didn’t need to have,” he said. “I had to educate the officer on what it was that he really needed to see in order to permit her to enter.”

Those who are denied entry with a tourist visa likely would just be sent back to their country of origin. Those with other kinds of visas, like student or work visas, could be sent back and instructed to obtain additional paperwork before trying again, which can be an extremely lengthy, costly and tedious process, Herman said.

“I have some clients who have been denied for weeks waiting for visas to be issued and they can’t get back into the U.S.,” he said.

Some green card holders have been pressured by border officers to sign an I-407 form if they have stayed outside the U.S. for more than six months. Signing this form relinquishes their permanent residency, Nachman said.

Do not sign anything, and demand to see an immigration judge if pressured to do so, the attorneys said.

“Stand your ground and explain to the officers that you understand the rules and the rules are that only an immigration judge can take away the green card,” Nachman said.

If You Must Travel

Travelers are advised to seek legal counsel before leaving the U.S. if there are any questions or concerns about being detained during reentry. Such concerns could relate to a prior arrest, their name being similar to someone else’s, a paperwork issue ― such as a passport having an incorrect date or misspelled name ― or their country of origin being on Trump’s proposed travel ban.

“If there’s any ambiguity, seek legal counsel before going,” Herman said.

Attorneys will go over travelers’ information and prepare personalized documents for them to carry should issues arise. Nachman said he also requests clients’ itineraries and for them to text him before and after they go through border checkpoints so he is on standby to help.

If you obtain legal aid, ask a friend or loved one who’s on the ground nearby to reach out to you within a certain time of you reaching a border checkpoint to ensure you got through securely, Sichta advised.

Herman said he hopes that the information he supplies clients before their travel could serve as a kind of “virtual representation” since he can’t otherwise be there if something goes wrong.

“I couldn’t be physically there, even if they paid me,” he said. “But they could have virtual representation, in terms of, ‘Hey this is what the lawyers are saying.’ We would hope that if they go into secondary inspection then that packet could be used and shown to a supervisor and the supervisor could intervene. Say, ‘OK the lawyer is saying this and this. This looks legitimate.’”

Attorneys also recommend leaving electronics at home, carrying a secondary “cold” phone that contains no personal information or even mailing a clean phone to yourself at your final destination to avoid potential issues.

“Is it a pain and expensive? Yes. What’s worth more: Having to get you out of jail or having to get a new phone?” Sichta said. He also recommended turning off the facial recognition feature that unlocks the phone so it can’t be opened without the user’s consent.

“Lock that phone, even if it’s a cold phone. Let them have it if you’re a green card holder but know that you don’t have anything in there that’s going to harm you anyway,” he said.

The Short Advice

Anyone who is not a U.S. citizen should avoid nonessential travel right now. This includes permanent residents, or so-called green card holders, the attorneys said.

“I’m telling my clients, you cannot put your families through this, or yourself. Do not go,” Sichta said.

“That’s the bottom line, because the border is very volatile right now,” Herman said.

“If you want to reduce the risk of having your visa revoked at the border or encountering problems, if you want to reduce that risk 100%, don’t travel,” Nachman said.

If A Problem Arises

Reach out to an attorney for help. Organizations like CAIR can help provide legal representation for clients with lower financial means. Those who don’t qualify can still be referred to an accredited lawyer.

“If nothing else, we take pride in getting them into good hands,” Sichta said.

A list of pro bono (free) legal service providers also can be found here on the Justice Department’s website.

If you feel like your civil rights, or the rights of someone else, have been violated by a U.S. Border Patrol officer, complaints can be filed with the Department of Homeland Security.

Anyone searching for a missing loved one after they passed through border security can search the U.S. Immigration and Customs Enforcement’s database of detainees. The website lists those who are currently in custody or who have been in CBP’s custody for more than 48 hours.

If the individual cannot be found there, contact an ICE Enforcement and Removal Operations (ERO) field office.