This became an issue with us just recently with our six month old, June. We have milk crates of toys set out for our two girls but I think whenever the younger one would get a toy the older would take it away. This led June to get things that our older dog knew were not hers and would not them away.
We lost four books in one day, she would have one destroyed in 10 minutes.
We started some new training technique of the "not yours game"
Line a whole bunch of things on the floor, some dog stuff some not. When she goes for her things you say good girl and treat. When they go for the book or remote so loudly "not yours"
Practice everyday for a week, it has since stopped the madness, for the most part.