Kevin Systrom says in a blog post:
Instagram users own their content and Instagram does not claim any ownership rights over your photos. Nothing about this has changed.
Instagram’s new terms say:
Instead, you hereby grant to Instagram a non-exclusive, fully paid and royalty-free, transferable, sub-licensable, worldwide license to use the Content that you post on or through the Service […]
My point being: does it really matter whether Instagram technically “owns” your photos if they claim most of the individual rights usually associated with ownership, such as licensing?
The word “own” is a technicality here. I notice Mr. Systrom didn’t try to explain the addition of the words “transferable” and “sub-licensable”.