Thousands of U.S. immigrants are on track to miss a critical Thursday deadline to extend their protection from deportation—because they're scared.

When the Trump administration announced last month that it would end the Obama-era Deferred Action for Childhood Arrivals program, Attorney General Jeff Sessions said that some 154,000 immigrants could apply for renewal before their protected status would expire — if they took action before this Thursday. But at close of business Wednesday, only 112,000 people have submitted the necessary paperwork, a U.S. Citizenship and Immigration Services spokesman told Newsweek.

Activists say a large chunk of the missing 42,000 eligible Dreamers, as they're called, have refused to apply out of fear. They're worried the anti-immigrant Trump administration will use the identification and contact information to force them out of the only country they've ever known.

"There's a sense of trust being grossly violated," Carlos Guevara, a senior policy advisor with the nonprofit UnidosUS, told Newsweek. "There's a concern of, 'Why would I come forward again?'"

Related: What Is Going to Happen to the DREAMers After Donald Trump’s DACA Decision? 

President Barack Obama launched DACA in 2012 so that undocumented immigrants brought to the U.S. as children could go to school, get jobs and receive benefits like driver's licenses without worrying they'd be removed because of their illegal status. About 800,000 people came out of the shadows—but on September 5, President Trump ended the protections, punting the issue to Congress, which has not acted.

But pro-immigration groups have. Guevara says his organization spent the past month scrambling to notify eligible Dreamers to get their applications in, though many are reluctant to give their full legal name, mailing address, date of birth, gender, marital status, country of birth and other vital info to a government that has sent mixed signals at best on immigrants.

"Within the community, there is a lot of concern, frustration, anger, sadness—the range of emotions about what the decision means for them," he adds. "My question is whether they'll take the next step to apply."

Legislation is pending to address DACA, but it's slow-going and divisive.

Senators Dick Durbin, a Democrat from Illinois, and Lindsey Graham, a Republican from South Carolina, are pushing a bill that would allow immigrants to get lawful permanent residence and citizenship if they meet certain conditions. A trio of Republican senators—North Carolina's Thom Tillis, Oklahoma's James Lankford and Utah's Orrin Hatch—have introduced other legislation.

Alex Solomiany, an immigration attorney in Miami, Florida, says the uncertain timeline of those bills has made many Dreamers nervous.

"There's been so much talk back and forth, you get it from both sides. 'Why should I renew now? Why am I going to give them my most recent information? Because they'll use it against me when it expires,'" he says. "They're afraid to file because they don't know what's going to happen come March 5, 2018" when DACA expires for good.

It is unclear what the Trump administration would or could do with the information. The Department of Homeland Security has said that "generally, information provided in DACA requests will not be proactively provided to other law enforcement entities," such as Immigration and Customs Enforcement and Customs and Border Protection, but there's a caveat: "unless [the immigrant] poses a risk to national security or public safety."

And the Trump administration has defined the term "risk" broadly, covering undocumented immigrants who have not been convicted of any crime beyond their illegal status.

ICE has said it's most concerned with immigrants who have significant criminal records. But nearly 20,000 of the immigrants arrested between January and June 2017 weren't convicts, according to CNN. That's more than double the number that were detained during the same period in 2016.

The anxiety some DACA recipients are feeling prompted Texas Representative Beto O'Rourke to introduce the Protect DREAMer Confidentiality Act of 2017, which would bar the secretary of Homeland Security from releasing a Dreamer's personal information to enforcement officials.

"It's not an irrational decision on the part of someone not to come forward," O'Rourke, a Democrat, told Newsweek. "What would give folks some confidence to renew is to have something like this bill in place as law."