Here's an unusual story. An Illinois woman suspected that her husband was being unfaithful. Unbeknownst to her husband, she had copies of his emails forwarded to her own account and received his correspondence with several women. When the husband learned of the electronic spying, he sued his wife.
Her action was clearly illegal, but federal judge Richard Posner turned this back on the husband, citing a rarely enforced Illinois law that makes adultery a crime. He concluded that the wife was stopping a criminal, and doing a public service, kind of like a bounty hunter. He actually said that in his ruling.
Okay, that's a pretty wacky legal rationale for ruling in favor of the defendant, but I suspect that underlying his opinion, Judge Posner was applying a bit of wisdom about humanity, perhaps because he understands how irresistibly tempting it would be for a betrayed spouse to snoop on a likely cheater. In fact, in my practice, I've had many patients tell me of doing exactly what this wife did. They've tapped phones and recorded calls (I twice had police officers do this in the 1990s), put trackers on cars, they've installed keyloggers on computers, hacked email and hacked texts. I've heard it all.
The snoopers all know it's a illegal (I tell them 'IANAL, but I know that's illegal'), but they feel gaslighted by cheating spouses and want to end the torment. I get it, and I think Judge Posner gets it.
What I've also learned is that if you feel compelled to take such extreme measures to snoop on a spouse, the spouse is almost certainly cheating. I'm sure there are exceptions, but I can't remember a case in which the suspect wasn't in fact detected as a cheater.
I've been an admirer of Judge Posner for decades. He's a brilliant jurist and scholar, with a strong grasp of economics, a big free market guy, but not a blind ideologue. He's also very outspoken -- in a good way. I also think he has considerable wisdom, and so his ruling in the snooping-spouse case might not come as a complete surprise to those familiar with him.