Date: April 14, 2026 Subject: Comprehensive analysis of the "Block" feature on Facebook. 1. Executive Summary Blocking is Facebook’s most restrictive privacy and safety action. When User A blocks User B, it creates a near-total digital separation between the two accounts. This action is asymmetric (User B does not receive a notification) and reversible (Unblocking is possible but has specific limitations). The primary purpose is to prevent harassment, unwanted contact, or exposure to specific individuals. 2. Immediate Effects of Blocking Once a block is activated, the following changes occur instantly: