Executive Summary
Consolidated all 4 child task findings into BACKGROUND_CHECK_RESEARCH_MASTER.md (255 lines). Ranked 43 sources into 4 tiers: Tier 1 (4 proven-working free tools — Holehe, h8mail, WHOIS, HIBP), Tier 2 (3 low-cost APIs — Numverify, Hunter.io, EmailRep), Tier 3 (8 OSINT tools worth installing), and Tier 4 (17 enterprise/paid sources to skip).
📊 Key Findings
Built automation viability matrix showing what's automatable vs. manual-only across 7 categories. Defined 4-phase scope: Phase 0 Setup (2hrs/$0) through Phase 3 Multi-Subject (16-22hrs total, $0-25/mo). Documented legal/ethical constraints (FCRA, consent, TOS). Core finding: Scott's minimal digital footprint simplifies the build — 4 tools cover everything automatable today.