[ratww]

I remember WhatsApp used to save each received image to the iCloud Photo Album. I remember one day going to my album and seeing several memes and pics I had received but never saved.

Having 3rd party apps that have access to the photo album being able to do that makes it a bit risky to have iCloud.

[EtienneK]

WhatsApp was my first thought as well. Any app that automatically saves photos to iCloud without user interaction is a huge risk.