TL;DR:

ICE contractor ShadowDragon uses their platform SocialNet to map individuals' digital footprints, personal data and connections across 200+ sites such as OnlyFans, WhatsApp, Roblox and Duolingo.

ShadowDragon claims it accesses data in real-time without storing it, sidestepping some accountability.

ICE and other agencies, including the DEA and State Department, use SocialNet for investigations, citing its utility in tracking criminal activity, despite their unwillingness to prove that criminality in court.

Link to the 404Media article without the required sign in.

Link to Mozilla's follow-up article which mentions some additional involved companies.