Found this on Telegram. Unfortunately, no attribution, but then again is it a leak.
ICE: ‘SMARTPHONE’ PROGRAM INEFFECTIVE: A leaked draft of a 2020 internal ICE report states that the “Alternatives to Detention” program, which has cost $1.46 billion since it started in 2004, has “little value.” The program uses ICE-provided ankle monitors and smartphones using the SmartLink program for tracking illegal immigrants released by authorities. An average of 84% of illegal immigrants leave the program, ditch devices, or delete tracking applications to live in the United States illegally. Some 216,000 illegal immigrants are currently enrolled in the program. – R.P.
My guess is that the only reason for them to track illegal aliens is so they can send reminders to vote for the American Communist Party candidates at election time.