# Citizen Lab Exposes Webloc Surveillance System Tracking 500 Million Mobile Devices via Ad Data

_Saturday, April 11, 2026 at 8:03 AM EDT · Cybersecurity, Policy · Latest · Tier 1 — Major_

![Citizen Lab Exposes Webloc Surveillance System Tracking 500 Million Mobile Devices via Ad Data — Primary](https://citizenlab.ca/wp-content/uploads/2026/04/COBWEBS_illustration-01.jpg)

A new investigation by University of Toronto's Citizen Lab has revealed details of Webloc, an advertising-based geolocation surveillance system that provides law enforcement access to location records from up to 500 million mobile devices.

The research identified Hungarian domestic intelligence, El Salvador's national police, and multiple U.S. law enforcement agencies as users of the technology. Webloc was developed by Israeli company Cobwebs Technologies and is now sold by Penlink following the firms' merger in July 2023.

Location data collected from mobile applications and digital advertising can reveal detailed patterns about individuals' habits, interests, and daily movements. The system offers a constantly updated stream of records, enabling persistent tracking on a global scale.

The findings highlight ongoing concerns about the surveillance capabilities available to government agencies through commercial data brokers and the advertising ecosystem.

## Sources

- [The Citizen Lab](https://citizenlab.ca/research/analysis-of-penlinks-ad-based-geolocation-surveillance-tech/)

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Retrieved: 2026-04-21T15:05:23.237Z
Publisher: Tech & Business (techandbusiness.org)