Perhaps we should obtain the opinion of those who were under surveillance prior to the development of technologies, such as phone-tapping, etc.

I knew of two such people, Australians, who had been among the first to be expatriated from Europe in 1943. They did not know each other, but on arrival had attracted the interest of the Federal Police. Their lives were made a living hell.

They under constant surveillance, but also had to keep diaries of all who approached and spoke to them and whom they approached, along with conversation. Indeed any social interaction, no matter how banal.

Before going anywhere they had to provide details of where, why, , etc .. even for the most mundane of business.In fact, they had to get 'clearance' to do so.

Neighbours were 'conscripted' to spy on them, collecting evidence of anything suspicious and including movements of the individuals in their own homes. So assiduous were they, that it was tantamount to a witch-hunt. This role was not confined to neighbours, but also employers and workmates.

Mail was intercepted, invasion of their residences, whether anyone was at home or not, was commonplace. Everything gone through and often items were removed. In one instance, the brother who was fighting in New Guinea, had built a small radio (his hobby), this was smashed.

All friends were under suspicion, including those those past, who had just been school pals. Apart from being interrogated, they had to hand over any letters they had received from these 'suspects'. Having gone to Europe as young woman prior to the war. one had written of the gorgeous young Italian policemen she had seen on point duty,observing that she'd love to smuggle them back home in her luggage. This was taken as evidence of her fascist leanings.

They were regularly brought in for interrogation which lasted many hours, along with threats of 'we won't get rough unless we have to.'
One woman observed to me, that having been interrogated by the Gestapo ...

cont ..

When she unknowingly 'lost her tail' walking to her bus-stop, she was hauled in and interrogated at length as to why, and where had she gone etc. etc.

Both these people said 'if only there had been phone-tapping, or other technology available then, they wouldn't have had to endure these horrors. They added that they would have welcomed such technologies, no matter how invasive.

As other writers above have pointed out so well, so much is now available - Many people seemingly have a desperate need to publicly convey their most intimate activities online. On the other hand, others put an over-inflated importance, in the wider scheme of things, on what they consider 'private.'