I never reveal my body on the internet

To tell them they were revealing too much I googled the supermarket, found the grassy area, noted the diagonal path worn into the grass, indicating street direction. Google maps street view quickly showed the matching view from their bedroom window. It also revealed the street name and the door number. We then went to their (non-private!) Facebook page and perused their interests and pics they posted of their family and friends, and also pics they had posted on other websites as well. A friend and I went on to find a website where they posted pics of the home improvements they had done to their home and we got the back view of the house and garden as well, plus their van parked out front and the reg number. We could even make out the holiday stickers in the van window, so we knew where they had been holidaying. Using the name and so forth we got their home phone number, too. We called it a day at that point, having proved our case.

Silly man, that's not stalking. They had put the info there for people to see, to the point it was getting risky. We made them aware and that was it.

What you did is stalking. It doesn't matter whether the information is public the collating of it and the unwanted or repeated surveillance by you against another person is, by any definition, stalking.

Using your argument a rapist could argue that he was merely showing how dangerous it was for women to be out on the street alone.

If you want to know how much you give away of yourself and your life and family circumstances, just ask the forum to list the things they know about you.
You'll be surprised!!

Indeed but that's part of belonging to a small forum IMO if I want true anonymity I use a big anonymous forum and protect my privacy accordingly. I like to think of us a group of friends, certainly that was the forum I joined, many of us revealed more than people are now doing. Hardly anyone was an unknown entity a few years ago.