The best reason for a company to establish social media policies is to:

Organizations implement social media policies primarily to limit legal liability by clarifying acceptable online behavior, protecting confidential information, and preventing harassment, defamation, or regulatory violations.

Official Extract:

"Establishing employee policies regarding communication technologies, including social media, protects the organization against liabilities related to defamation, discrimination, data breaches, and intellectual property theft."

(Source: HRCI PHR Content Outline 2024–2025, Business Management Section, Risk Mitigation and Compliance)