EL PASO, Texas — Federal authorities' shift away from separating immigrant families caught in the U.S. illegally now means that many parents and children are released and fitted with electronic monitoring devices — which both the government and advocacy groups oppose for different reasons.

U.S. Immigration and Customs Enforcement is issuing thousands of 5.5-ounce (155-gram) ankle monitors that immigrants call grilletes, or electronic shackles. The government says they get people to show up to immigration court, but that they stop working once deportation proceedings begin.

Attorneys and people who wore the devices or helped monitor those wearing them say that's because some immigrants simply ditch them and disappear.

Immigrant advocates and legal experts argue, meanwhile, that the devices — which are commonly used for criminal parolees — are inappropriate and inhumane for people seeking U.S. asylum.

Congress first established the program in 2002, though GPS monitors' use increased even more after 2014, when thousands of unaccompanied minors and families began traveling to the U.S.-Mexico border and asking for asylum, fleeing gang and drug smugglers or domestic violence in Central America.

Earlier this year, immigrant families were separated as part of a "zero tolerance" program. But after a presidential executive order reversed that, families are often detained, then issued ankle monitors and released as they progress through often lengthy immigration court proceedings.

Sandra, who asked that her full name not be published, so as not to jeopardize her case, said she left northern Guatemala in May with her 12-year-old son, Juan Carlos. She said she had faced discrimination because of her dark skin, and also was attacked sexually by a man who threatened to kill her if she went to the police.

They were held in different Texas detention centers for nearly two months, then reunited and released — but she got an ankle monitor.

"I feel tortured," said Sandra who said she fled Guatemala "I'm not in one of those detention centers, thank God, but I still feel like I'm a prisoner."

As of early July, there were nearly 84,500 active participants in ICE's Intensive Supervision Appearance Program, or alternatives to detention — more than triple the number in November 2014. Around 45 percent of those were issued GPS monitors.

ICE spokesman Matthew Bourke said immigration court attendance is strong for immigrants in intensive supervision, but that ankle monitors and other measures are "not an effective tool" after deportation orders are issued. There isn't reliable information on the number of ankle monitor recipients who remove them and flee, but many say it's high.

"People can just cut those things off if they want to," said Sara Ramey, a San Antonio immigration attorney whose asylum-seeking clients are routinely assigned ankle monitors.

The most recent available data was in 2012, when a contractor's annual report showed that 17,524 people, or around 65 percent of nearly 40,500 total participants, left the intensive supervision program that year. Of those, around a fifth were deported or granted asylum, while about 5 percent "absconded." The rest were arrested, violated other program rules or were no longer required to participate for unspecified reasons.

President Donald Trump's administration sees alternative to detention programs as undermining their larger goal of keeping immigrants in custody, which helps lead to faster deportations.

Overall spending on alternatives to detention rose to $183 million for fiscal year 2017, up from $91 million in 2014. But the number of deportations for people in the program only increased by 273, from 2,157 to 2,430 — or only about 1 percent of the more than 226,000 people ICE deported over the same period, Bourke said.

Ankle monitors have been a boon to the company that has a federal contract to administer them, Boca Raton, Florida-based GEO Group. Its stock has outrun the larger bull market since Trump took office.

If an ankle monitor's rechargeable battery dies, or its wearer ventures out of his or her assigned area, alarms are triggered and orders are barked in Spanish. Immigrants issued ankle monitors also usually check in personally with case workers.

Near Houston's George Bush Intercontinental Airport around 70 people, almost all women, were waiting to see case workers. Maria, 40, showed off her monitor and bruised ankle. She said she'd fled Honduras after gang members threatened to kidnap her daughter but asked that her surname be withheld, citing safety concerns.

Many men with monitors "cut them loose and take off," Maria said.

Two former case workers with a GEO subsidiary, who spoke on condition that they not be named because they wanted to safeguard their future employment chances, said it was common for ankle monitors to be removed prematurely, and people who do are rarely pursued.

"ICE has other priorities," said one ex-case worker.