Senators pressure eight digital advertising exchanges - including Twitter, Google and AT&T - to disclose who is collecting what specific user data during the real-time bidding process.
New privacy-focused rules banning location trackers and requiring disclosing data collection rules for privacy are not consistently enforced on the App Store and Google Play.
Google said tests show that the new technology to replace third-party cookies doesn't impact ad revenue, but didn't provide more details on how it would enhance user privacy.
In Firefox 85, Mozilla is partitioning several caches in the browser in order to prevent trackers from abusing them.
New York lawmakers are moving ahead with their own privacy legislation to regulate how private companies handle biometric data.