How can i stop others' downloads from automatically downloading onto my itunes?

I share an Itunes account with my family, but we all have separate itunes on different laptops. Evertime anyone downloads a ton of apps or music I dont like, it automatically downloads onto my itunes the next time i open it up. Although i could just pause the downloads and delete them all, they all come back and start downloading again the next time i open up itunes. I only want my music and my apps, how can i stop this!?

Thanks for any help!