This is what will happen, and this is the final straw.
I've had inane and meaningless comments posted to my media contributions in the past and I have only very little media posted. I cannot imagine for people who have large amounts of media.
But, in the past, this was no big deal - I just deleted the inanities and went on my merry way.
Given that I no longer have control of contributions to my own tree, and given (based on experience) that I don't trust Ancestry to acquiesce - or even respond promptly - to my wishes regarding my own tree, I'll be removing my few dinky media contributions and recreating my tree as private.