Covert Web-to-App Tracking via Localhost on Android
Meta -- never not At It.
Facebook/Instagram used a sneaky localhost socket connection to correlate web visits with Meta user ids and track web/app user identity without any explicit permission.
"the novel tracking method works even if the user:
- Is not logged in to Facebook, Instagram or Yandex on their mobile browsers
- Uses Incognito Mode
- Clears their cookies or other browsing data
This tracking method defeats Android's inter-process isolation and tracking protections based on partitioning, sandboxing, or clearing client-side state."