What to Know Two undocumented Mexican grandparents were locked up while trying to visit their soldier son-in-law at Fort Drum on July 4

The couple was detained after presenting their IDNYC cards; weeks ago, a pizza deliveryman with his own IDNYC was detained at Ft. Hamilton

Now undocumented immigrants are worried that IDNYC cards could actually be tipping feds off; but advocates say IDNYC is safe

UPDATE: Immigrants Now Urged to Steer Clear of Using IDNYC Cards at Federal Facilities

After two Mexican grandparents were locked up on immigration charges while trying to visit an Army base to celebrate Fourth of July with their soldier son-in-law, immigrant advocates are trying to assuage fears that the New York City-issued cards they presented actually tipped off federal agents.

Concepcion and Margarito Silva, undocumented Mexican immigrants who have lived in New York for two decades, went to Fort Drum on Independence Day to visit their son-in-law, an Army sergeant in the 10th Mountain Division. When they presented their IDNYC cards, border patrol agents there questioned their IDs and then took them to a detention facility hundreds of miles away.

Army spokeswoman Julie Halpin said the Silvas were asked for secondary identification because IDNYC cards do not have barcodes like the ones on the back of state driver's licenses.

"The bar code brings us a photo of the individual that we can check against the ID and the person presenting it," Halpin wrote in a statement to News 4 New York. "NYC IDs do not have this bar code. That is why they were asked to present a second form of ID."

The Silvas' son, Eduardo Silva, has said his parents had used their IDNYCs to access military bases before. This time, when they were stopped by military police, the Silvas admitted they were in the U.S. illegally, according to Kris Grogan, a spokesman for Customs and Border Protection.

"On July 4, the United States Border Patrol received a call from the Fort Drum Military Police regarding two individuals attempting to gain access to a federal facility," Grogan wrote in an emailed statement. "Border Patrol Agents responded and interviewed the couple who admitted to being illegally present in the United States. Both subjects were charged with being Present in the United States without Admission or Parole."

The official IDNYC was an immediate hit when it launched in 2015, with 50,000 people signing up to enroll in the program the first week. It's aimed at those who do not currently have a government issued ID -- including the elderly, homeless and an estimated 500,000 undocumented immigrants in the city -- to help them obtain key services, like opening a bank account or getting a library card.

After President Trump was elected, there was concern that the federal government would try to access IDNYC records to deport people. Mayor Bill de Blasio has vowed to not let the federal government get the records, and said the city won't keep personal records from future applicants.

Now New York gubernatorial candidate Cynthia Nixon is challenging Gov. Andrew Cuomo to make driver's licenses accessible to undocumented immigrants.

Nixon, who has called for the Silvas to be set free, suggested that Cuomo could have prevented their arrests in the first place by ordering undocumented immigrants have a chance to apply for standard driver IDs.

"Something the governor could do by executive order - and what I will do when I'm office - is allow undocumented immigrants access to a driver's license," Nixon said.

Cuomo, who has said he also supports driver's licenses for undocumented people, insisted he needs legislative approval to change the rules.

"The Senate Republicans will not pass it. Period. We need a new Senate," Cuomo said.

A month before the Silvas were arrested by Border Patrol, another undocumented person was detained after presenting his IDNYC at the gates of Fort Hamilton in Brooklyn. Pablo Villavicencio-Calderon, a married father of two, was delivering pizza and presented his ID like on other occasions bringing pizza there, but was detained. Though a federal judge has temporarily blocked the deportation of Villvaicencio, he has been in ICE custody in New Jersey -- and will continue remain in ICE custody -- until his case goes to court.

Despite the two high-profile arrests, Luba Cortes at Make the Road, an immigrant advocacy group, said people should be confident that IDNYC is a valid form of identification.

"Many undocumented people go to detention centers to visit their love ones and present their IDNYC and have no problems. So we really don’t know why they have problems when they go to those places (like military bases)," she said.

"There could be a change in protocols that came from the administration -- but we don’t want to scare people, the ID is safe and we don’t want them to stop using it," said Cortes. "The best scenario would be to be able to expand the program outside of the city."

Khaalid Walls, a spokesman for Immigration and Customs Enforcement, said the Silvas have no known criminal history and no previous contact with ICE.

The Silvas' children are not only concerned their parents might be deported; they're concerned about their health while incarcerated.

"We don't know what could happen to them in there," said daughter Dulce Silva as she cried last Friday. "It would be crazy if they didn't make it out of there."

"I don't understand why people pick on people that just want to work and live their life without any troubles," said Eduardo Silva.

Another daughter, Perla Silva, broke down on Monday as she asked ICE to let her parents go, recalling how her daughter saw her grandparents being handcuffed.

"We ask ICE to release our parents immediately," she said.