The Cyber Security and Infrastructure Security Agency's (CISA) Cybersecurity Division (CSD) continues to improve its ability to defend federal civilian Executive Branch agency networks from cyber threats. Similar to EINSTEIN 1 and EINSTEIN 2, DHS deployed E3A to enhance cybersecurity analysis, situational awareness, and security response. With E3A, DHS will not only be able to detect malicious traffic targeting Federal Government networks, but also prevent malicious traffic from harming those networks. This is accomplished through delivering intrusion prevention capabilities as a Managed Security Service provided by Internet Service Providers (ISP). Under the direction of DHS, ISPs will administer intrusion prevention and threat-based decision-making on network traffic entering and leaving participating federal civilian Executive Branch agency networks. This PIA was conducted because E3A includes analysis of federal network traffic, which may contain PII.