Spying is something those in power always do. They have been spying on people since long before the 1970's, when Motorola introduced the when first handheld mobile phone, here's some examples:

Spying using Interception and mail opening on letters sent through the postal service from the 1770's.

Spying using Wiretapping on text messages sent by telegraph from the 1840's.

Spying using eavesdropping on telephone calls routed through an exchange from the 1870's.