Hacker News Reader

> Budding spies and others of a paranoid nature can buy a couple of those SIM cards to swap in and out of their (unlocked) phones for $10 in any 7-11, no registration, no questions asked (try doing that in India or Argentina!)

Argentine here, you can buy SIM cards literally everywhere. Vendors will even sell them to you on trains.

View on HN

Logging on to GSM your phone uploads its IMEI ('phone serial number') with the SIM card identifier or IMSI ('sim ID'). So if you switch, you are still tracked. Budding spies will learn their tech before putting their ass on the line.

As mentioned further up these comments, IMEI's can be forged, and phones produced "off-hours" in the factories often have IMEI's consisting of all 0's or all 1's. I gleaned this much just from reading this thread.

Sure. Also, according to recent quotes from Snowden, this is the primary mobile communciations key the NSA maintain records and search by... not phone number.

Reply on news.ycombinator.com