Apparently, this has been loudly complained about from at least Aug. 27, 2011 through as late as Sep. 15, 2013:
In Canada, it turns out that we even own photos we took for someone else.
Why you want to mess with my photos, Google?
One reply on “Google Instant Upload’s Nag:
“Make That Photo Public””
[…] only took 4 years or so, but you’re listening! Sweet. […]