The Short Version
No credible, independent evidence supports the claim that smartphones actively listen through microphones to serve targeted ads. The primary supporting evidence — a leaked CMG marketing pitch deck — was walked back by the company itself. Independent scientific studies, including a Northeastern University analysis of 17,000+ Android apps, found no unauthorized microphone activation. The "eerily accurate" ads people experience are well-explained by extensive metadata collection: location data, browsing history, app usage, purchase records, and cross-device tracking — no eavesdropping required.