| “Wiretap” without additional context is a bit misleading since in conjures an image of listening to phone conversations between employees of the competitor. I think it may be fair to call it wiretapping but it’s different from that image. They paid users to install an app on smartphones that spied on network requests made by those users. In iPhone this app used OS VPN support to intercept traffic, and a root CA certificate to treat the intercepted connection as legitimate. “Proxyman” is an iOS app that does the same thing on behalf of the user - it’s super helpful for debugging your own app or reverse engineering someone else’s app. I used it to reverse engineer the API of my smart home gym app Tempo Fitness so I could build my own dashboards from my workout metrics. Facebook used this technique to “wiretap” the analytics log events that Snap and the other apps were sending to themselves - events probably look like “user swiped to next video after viewing video id=1234 for 3 seconds” or “user clicked ad id=5678”. TechCrunch report on Facebook Research (2019): https://techcrunch.com/2019/01/29/facebook-project-atlas/?gu... The Wikipedia page for Onavo (the startup Facebook bought that that powered this stuff) is pretty clear and has good citations for additional reading: https://en.m.wikipedia.org/wiki/Onavo |