ICE uses a wide mix of government databases, private “people‑finder” tools, and new surveillance platforms to dig up information on people, including many who are not suspected of any crime, and several aspects of this system are under serious legal challenge today.nilc+1
Criminal and immigration databases
FBI and DHS fingerprint/biometric systems are automatically checked when someone is arrested under the “Secure Communities” program, which can trigger immigration enforcement even in cities that try to limit cooperation.nilc
ICE also uses federal immigration databases and a dedicated “Gang File” connected to systems like GangNET and the FBI’s NCIC to flag people as suspected gang members, often with poor accuracy.nilc
State and local data pipes
ICE can pull information from state criminal‑justice networks and Nlets, a state‑owned network that gives access to arrest records, convictions, and DMV data such as addresses and license plates.nilc
Local police sometimes share driver and arrest information informally with ICE, even where local law or policy is supposed to restrict this.aclu+1
Commercial data brokers and “skip‑tracing” tools
ICE has multi‑million‑dollar contracts with data brokers like LexisNexis and Thomson Reuters that provide tools such as Accurint and CLEAR, which compile names, addresses, court records, utilities, phone, employment, and credit‑linked data into searchable dossiers.borderlessmag+1
Lawsuits allege that these tools enable “warrantless surveillance” by letting ICE track daily address changes, incarceration status, and credit‑activity updates, effectively bypassing local sanctuary protections.icirr+1
License plate and location tracking
Over 9,000 ICE agents have had access to a massive automated license plate reader database run by Vigilant Solutions, containing billions of scans from police, parking lots, and private companies, allowing long‑term tracking of drivers’ movements.inthesetimes+1
Documents show DHS, including ICE, has bought large amounts of cellphone‑based location data from private companies, letting agents track people’s movements over time without going directly to phone carriers.aclu
Palantir / “ImmigrationOS” and new AI‑style tools
ICE uses a Palantir‑built system sometimes called “ImmigrationOS” to pull together IRS data, immigration records, and private databases into a single interface, making it easy to search across many sources for a specific individual.eff
Recent reporting shows ICE has purchased tools like “Tangles” and “Webloc” to analyze phone and internet data, including tracking the cell‑phone activity of whole neighborhoods for investigative purposes.mprnews
Publicly known
Many of these systems are now documented through contracts, FOIA releases, and court filings, including the use of LexisNexis/Thomson Reuters, Vigilant license‑plate data, Palantir systems, and data‑sharing via Secure Communities and Nlets.eff+3
Congress, local governments, and advocacy groups have held hearings and published reports describing this “surveillance web,” so the existence of the tools is often public even if the internal rules and algorithms are not.icirr+1
Less visible / opaque parts
The full scope of what private datasets are ingested, how long data is kept, and how often systems like ImmigrationOS are queried is not publicly transparent.eff
Internal scoring methods (for “risk” or gang affiliation, for example) and some contracts or technical integrations are only partially disclosed or heavily redacted in public records.scholarship.law.uc+1
Formal legality vs. constitutional concerns
ICE and DHS argue that buying data and using these tools is lawful as long as they comply with existing statutes and internal policies, and companies like LexisNexis emphasize that their contracts require “responsible use” under governing laws.borderlessmag+1
Civil‑liberties groups counter that purchasing sensitive data (location history, utility records, credit‑linked data) is a way to dodge the Fourth Amendment’s warrant requirement, because the government obtains information it would often need a warrant for if it subpoenaed or searched directly.aclu
Court rulings against certain practices
In Gonzalez v. ICE, a federal court ruled that ICE’s practice of issuing detainers solely based on database checks (place of birth plus missing citizenship data) and without proper warrants violated the Fourth Amendment and exceeded ICE’s statutory authority.immigrantjustice+1
The same case and related litigation highlight that ICE databases can be inaccurate, and using them alone to justify arrests has been held unconstitutional in some circumstances.scholarship.law.uc+1
Ongoing lawsuits and investigations
Lawsuits against LexisNexis and others argue that selling massive dossiers to ICE facilitates illegal, warrantless surveillance of immigrants and circumvents state sanctuary laws; these suits are still being litigated, so the law here is unsettled.borderlessmag+1
Recent disclosures about DHS and ICE buying phone location data have prompted legal challenges and calls for legislation to explicitly require warrants for access to such purchased data.aclu
Some uses are clearly allowed today: looking up immigration status in DHS systems, using databases after a lawful arrest, and sharing information when required by federal law.nilc
Some uses have been ruled unlawful in certain states or contexts, especially detainers and arrests based solely on error‑prone databases without warrants or statutory authority.immigrantjustice+1
A large gray area remains around buying commercial data and using large analytics platforms, where courts and legislatures are only now catching up; many scholars and advocates argue these practices violate the spirit, if not yet always the letter, of the Fourth Amendment.scholarship.law.uc+1
If you say what part worries you most (license plates, phones, data brokers, or local police cooperation), a more focused explanation of risks and legal protections in that area can be laid out.