This was actually one of the first times/places Google really upset me from a privacy standpoint, back in 2012 or so: I had Google Glass, Explorer Edition, and it's software was written to upload any photo you took to Google Photos. As an Android device with USB support, you could download the photos direct on a PC, and delete them before it did so. However, if it had Wi-Fi and power and it had photos, Google uploaded them without consent.
They repeatedly refused to offer an option to disable photo sync, even when they added a whole settings bundle to manage the sync settings. (Essentially, they started letting you tell it to upload photos even over cellular data, but still neglected to add a "just don't upload the photos automatically" option.)
They repeatedly refused to offer an option to disable photo sync, even when they added a whole settings bundle to manage the sync settings. (Essentially, they started letting you tell it to upload photos even over cellular data, but still neglected to add a "just don't upload the photos automatically" option.)