Denali Real Estate in Scottsdale is revising its lease agreements after fining a tenant $4,000 for posting negative reviews, a practice that violates federal law. The FTC says non-disparagement clauses like Denali’s are illegal under the Consumer Review Fairness Act, which protects consumers’ rights to leave honest feedback. Denali’s broker has promised to remove the clause from all leases, while federal officials warn businesses against using such “gag clauses,” which can carry steep penalties.