Jon Brodkin, writing for Ars Technica:
“You may not serve or include any advertisements in your API Client,” the Mirror API terms of service state. “You may not use user data from your API Client for advertising purposes. You may not sell or transmit any user data received from your API Client(s) to a third-party ad network or service, data broker, or other advertising or marketing provider. For the avoidance of doubt, user data from the API Client(s) may not be used for Third-Party Ad Serving.”
But guess who can serve ads. Go on, guess.