My friend hadn't come out publicly yet. He could have been embarrassed or hurt if, instead of a polite heads up, the person had called a gossip columnist.
So consider that before we roll out the moral indignation over the cheaters being named and shamed in the Ashley Madison adultery website hack.
Never in the history of the world have so few had the power to damage so many lives so profoundly and so immediately. All it has taken is a group of computer hackers — maybe even just one or two — to put at risk potentially millions of marriages. Or friendships. Or jobs.
The hackers seem to have done it over a moral objection to adultery. But the fall-out will hurt people who have never cheated.
I've found three people I know in the database. Maybe you will, too. You can easily search for your boyfriend, your wife, your uncle, colleague, mum or dad. Like me, you'll probably be a little surprised at finding a name you know.
But what if the people you know hadn't signed up to the website and are the victims of a years-old prank? What if they have open relationships with their partners but don't want everyone to know? What if this database sits on the internet for years and, for years, employers can search people before they hire them? And this time, replacing a hacked credit card number won't make it go away.
Read also:
• I used Ashley Madison, now what?
• Why Ashley Madison's founder thinks cheating can help marriages
• Controversial US reality TV star named in hack
A few days ago, a Sydney radio station told listeners to call in and check if their partners were using Ashley Madison.
That's how a woman found out live on air that her husband had an account. Her voice broke and she hung up. They have two kids. That's the real-life impact of this hack on families.
Maybe she will eventually be grateful she found out what he was up to, but she probably won't be grateful her friends and their kids, and her kids and their friends will be able to search his name and know what he was doing and the unnecessary detail of the kinky private messages he was sending women.
Any moral outrage we may feel over this should be aimed fairly and squarely at the hackers. It really doesn't matter how much you hate the game, it's not your business to out the players. If history is anything to go by we'll never know who the hackers are and they will never be held accountable.
Just remember, nothing you do online is guaranteed to stay secret forever. So maybe just don't do it.