The big joke about privacy is that no one even bothers
In 1967, Justice John Marshall Harlan (one of the greats) wrote a concurring opinion that, to this day, establishes the constitutional test that protects our privacy from the government.
It happened that one Charles Katz went into a pay telephone booth to make two calls. In the days before cellphones, there were pay phones in translucent stalls, where you could close the door and no one was supposed to hear you.
Katz closed the door and made calls about betting wagers to New York and Los Angeles.
Unbeknownst to him, the government had planted a listening device on the outside of the booth and recorded the calls, which it then used to prosecute him.
On appeal to the United States Supreme Court, that conviction was reversed because it was secured in violation of Katz's 4th Amendment right to be free from unlawful searches and seizures. The test, as Justice Harlan memorably explained, was whether Katz had a "reasonable expectation of privacy" when he made those calls. Yes, it was a public phone booth, but the 4th Amendment protects "people, not places," the court ruled. Yes, there was no physical intrusion into the booth, but the 4th Amendment does not require trespass.
I read Katz when I was in law school, and wiretapping was the big issue. I taught it for decades, when all kinds of undercover investigations were at issue.
Those cases were easy, because in those days, it was reasonable to expect that even if you ventured out of your home, and certainly if you didn't, you did not lose all expectations of privacy.
On the way back from lunch the other day, my assistant and I stopped in a cosmetic store she had never heard of so I could see if it had my shade. She never took out her phone. She certainly wasn't looking for overpriced makeup.
When she got home, she was inundated with ads for the makeup.
Because her phone, supposedly asleep in her purse, was, of course, not asleep at all. It was busy communicating that she was in the store, as well as all the other things they already know about.