While apps are increasingly utilizing end-to-end encryption, push notifications usually cross Apple and Google's servers before appearing on users' smartphones. Governments are taking advantage of this fact to monitor users.https://www.notebookcheck.net/Apple-Governments-are-using-push-notifications-to-monitor-smartphone-users.780311.0.html
These declarations of corporations (and the senator's request) do not evoke anything from an educated person except homeric laughter, given the total real control that has long been carried out by all intelligence services and the real restrictions on hack-resistant cryptography.