…both foreign and U.S. government agencies have been asking Apple and Google for metadata related to push notifications to, for example, help tie anonymous users of messaging apps to specific Apple or Google accounts.

In a statement, Apple said that Wyden's letter gave them the opening they needed to share more details with the public about how governments monitored push notifications.

"In this case, the federal government prohibited us from sharing any information," the company said in a statement. "Now that this method has become public we are updating our transparency reporting to detail these kinds of requests."