Additional context:
https://san.com/cc/exclusive-evidence-of-cell-phone-surveill...>At 8:58 a.m., just before the protest began, SAN began monitoring eight LTE bands present in the area and found no anomalous behavior. At 9:06 a.m., however, a burst of 57 IMSI-exposing commands was detected.
>Other bursts, present on four of the LTE frequency bands, appeared roughly every 10 minutes over the next hour, causing Marlin to issue numerous real-time alerts. A post-scan analysis confirmed the detection of 574 IMSI-exposing messages.
>It also flagged two “attach reject” messages, a type of cellular rejection sent when a cell phone tries to connect to a network. Attach rejects can occur for valid reasons, such as when a phone with an expired SIM card tries to connect to a network but such messages are rare on properly configured networks. IMSI catchers may use attach reject messages to block or downgrade connections and obtain an IMSI before it is encrypted. SAN observed the two suspicious messages at 9:55 a.m. and 10:04 a.m. at the height of the protest but did not encounter others before or after the demonstration ended.
>SAN conducted a follow-up scan during the same time period, the following day, when no protesters were present. Unlike the day prior, Marlin did not issue real-time alerts.