Communications nodes, like wireline CO switches and (if it hasn't changed since 3G) mobile data nodes that support lawful intercept (LI) capability are required

Communications nodes, like wireline CO switches and (if it hasn't changed since 3G) mobile data nodes that support lawful intercept (LI) capability are required to be able to hide that (1% of the node capacity, IIRC) traffic from node operators, and to be controlled remotely from an LI console. It's a good bet that social networks, and especially their communications features need to support LI, with similar requirements. Twitters designated contact probably left the building in the first week of Elon.