Public data?
I don't think wifi data should be considered public, simply because there's no way to constrain it within my 4 walls without using a cable.
The point being, if they snooped on my voice calls that were going to nearby cell tower, that surely isn't public data. Or even if they took a photo of my bank details off a statement I was holding up where it was visible out of my window. It gives them no right to publish or use that information.