Wirelessly posted (iPhone 4 (32GB, JB): Mozilla/5.0 (iPhone; CPU iPhone OS 5_0 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A334 Safari/7534.48.3)
You an me both. Took a screenshot of me asking Siri something really stupid (to answer my friend's question of what it would say if I did) and boom! There it is in my photostream for my wife to see when she gets home ...
It's not only dumb stuff like that, but stupid pictures where you accidentally snapped the shot with your finger over the lens, etc. Seems kind of odd that NO ONE at Apple thought of giving people the option to delete photostream pics ...