I was doing something late at night (probably working on a hobby project, but I don't remember). I was just going to bed, when I got a warning notification that someone is attacking a portal near my flat. It was a player I came to recognize by nickname because she was constantly retaking the few portals that are next to my home. I decided it's an opportunity to finally meet her, to connect the nickname to a face, so I dressed up and run down to the park.
Upon arrival I met someone with a phone hiding in the shadows near a fence. I just stood there, countering her actions and waiting to be noticed. A kid yelled, "mom! are you coming?", to whom she replied "yes, just wait one minute". After that she noticed me standing there, so she told her kid to go and bring his dad. Moments later I was surrounded by three Ingress players and had to accept those portals are to be theirs that night.
We talked for about half an hour, exchanging stories about the city and Ingress community in it, all in completely friendly atmosphere. I haven't met them IRL again since then, but they take my portals over every now and then :).