An employer's best legal protection with regard to electronic surveillance of employees is to:

Consent is a cornerstone oflawful workplace monitoring. Employers must obtainwritten acknowledgmentfrom employees if surveillance (e.g., cameras, keystroke logging, emails) is used, particularly in jurisdictions with stricter privacy laws.

Extract from HRCI-aligned HR knowledge (Risk Management):

SPHR-level compliance frameworks require that “employee surveillance policies be transparent and consent-based.” This minimizes liability under privacy and wiretap laws, especially in multistate or international operations.