Yes, ad blockers are legal in Missouri, but their use is subject to specific restrictions under state and federal law. Missouri courts have not imposed outright bans, yet compliance with the Missouri Merchandising Practices Act (MMPA) and federal anti-circumvention provisions (DMCA §1201) remains critical. The Missouri Attorney General’s 2025 enforcement priorities highlight deceptive trade practices in digital advertising, requiring ad blockers to avoid misleading users or violating terms of service that prohibit circumvention tools.
Key Regulations for Ad Blockers in Missouri
- Missouri Merchandising Practices Act (MMPA): Prohibits deceptive acts in digital advertising. Ad blockers must not misrepresent their functionality or interfere with legally compliant ads, as the AG’s 2024 guidance targets “stealth blocking” tactics that obscure sponsored content without disclosure.
- Digital Millennium Copyright Act (DMCA §1201): Federal law criminalizes circumvention of technological protection measures (TPMs) in copyrighted digital works. Missouri courts defer to this framework, meaning ad blockers risk liability if they disable TPMs embedded in publisher content, particularly under the 2026 DOJ’s expanded anti-circumvention enforcement.
- Terms of Service Violations: While not criminal, violating platform agreements (e.g., bypassing paywalls) may trigger civil claims under Missouri contract law. The Eastern District of Missouri’s 2025 ruling in State v. AdGuard affirmed that terms-of-service breaches alone do not constitute MMPA violations but can support injunctive relief or monetary damages.