The conversation was if they need to ask for permission or not. Had nothing to do with what is reasonable. Facebook sucks still!
Imagine buying a new car to find out a day later that the engine is broken. You go back to the factory and ask for a replacement. They say sorry we can't verify you bought it here because our sales apartment doesn't share information with us so we can't replace it. Instagram and Facebook are the same company and they access the same data set.
From the freaking terms and conditions:
Instagram has been a part of Facebook since 2012, and we're making some corporate changes. Going forward, our Terms will reflect that Facebook Inc. is responsible for Instagram. [...] We also have a new Data Policy that explains how data is collected, shared and used in the Facebook Products, including Instagram. [...]
- The policy has more information about what we collect from your activity and our partners, how we connect information across the Facebook Companies and how we personalize your experience, including ads.
Here's thefull page with exactly what they share.