It is my understanding that Pocket by default phones home with the articles recommended to you as well as your interaction with them on the new tab page. Given

It is my understanding that Pocket by default phones home with the articles recommended to you as well as your interaction with them on the new tab page. Given that these recommendations are generated using your local browsing history they leak info. Based on your recommended articles they can determine what subset of the daily site set matches with your browsing history. A more focused attack could purposely poison the daily site set with obscure bad site(s); any users that receive these recommendation should have some browsing history intersection with the bad sites.