update: I tracked one down! It was beaconing from a small black device on top of a truck cab which looked a little like a Sirius satellite radio antenna with an extra vertical fin. It, as most of the others I’ve scanned, sent three mac addresses. No clue as to what the device was and I couldn’t make much more of it in the dim light. 🙁
What’s this? I had originally thought it was coming from onboard WiFi systems on Broward County Transit buses, or Broward parks, but it seems to have shown up in Palm Beach as well. First time i noticed a big cluster of them was near T.Y. Park, but I’ve seen lots more …. Clustered or alone.