US Immigration and Customs Enforcement is asking companies to provide information about “commercial Big Data and Ad Tech” products that would “directly support investigations activities,” according to a request for information posted on Friday in the Federal Register, the US government’s official journal for agency notices, rulemaking, and other public filings.

The posting says that ICE is “working with increasing volumes of criminal, civil, and regulatory, administrative documentation from numerous internal and external sources.” The agency frames the request as a way to survey what tools are currently available to help manage and analyze the information ICE has, saying it is looking at “existing and emerging” products that are “comparable to large providers of investigative data and legal/risk analytics.”

In addition, the entry says “the Government is seeking to understand the current state of Ad Tech compliant and location data services available to federal investigative and operational entities, considering regulatory constraints and privacy expectations of support investigations activities.” The filing offers little detail beyond that broad description: It does not spell out which regulations or privacy standards would apply, nor does it name any specific “Big Data and Ad Tech” services or vendors ICE is interested in.

The entry appears to be the first time that the term “ad tech” has appeared in a request for information, contract solicitation, or contract justification posted by ICE in the Federal Registry, according to searches by WIRED. The request underscores how tools originally developed for digital advertising and other commercial purposes are increasingly being considered for use by the government for law enforcement and surveillance.

In an unsigned statement emailed to WIRED, ICE stressed that the filing was solely for information and planning purposes. “Law enforcement across the nation leverages technological innovation to fight crime. ICE is no different,” the statement reads. ICE said it uses technology to support investigations and to aid in the arrest of criminals, “all while respecting civil liberties and privacy interests.”

The Department of Homeland Security did not immediately respond to a request for comment.

ICE has previously used the term “big data” in a contract justification for Palantir to provide “unlimited operations and maintenance support of the FALCON system” and unlimited licenses for “Palantir Gotham.” Gotham is Palantir’s off-the-shelf investigative tool for law enforcement. The company provides a custom version of Gotham to ICE known as the “Investigative Case Management” system. FALCON is a tool within the customized Palantir system that ICE uses to “store, search, analyze, and visualize volumes of existing information” about current and former investigations.

ICE has also previously purchased products that provide mobile location data, which is sometimes among the information provided by companies that buy and sell information collected for online advertising. Ad tech data can include details about the device and apps a person is using, where they are located, and their browsing activity, among other information.

ICE has purchased commercial location data obtained from Webloc, a tool sold by the company Penlink. Webloc allows a user to collect information about the mobile phones being used within a specific area during a particular time period. Users have the ability to filter the devices displayed according to criteria such as whether their location was gathered via “GPS, WiFi, or IP address,” or by their “Apple and Android advertising identifiers,” according to reporting by 404 Media,

In several recent years, ICE has also purchased licenses to use Venntel, a data broker and subsidiary of the firm Gravy Analytics that collects and sells consumer location data. In a Federal Registry entry closing out a contract with Venntel last year, ICE reported that its Enforcement and Removal Operations division had used the company’s software “to access/gain information to accurately identify digital devices.”