AppCensus’ analysis found that 18,000 Android apps with thousands to hundreds of millions of installs violate Google Play’s advertising ID policy, collecting user’s permanent device identifiers such as serial number, IMEI, WiFi MAC address, SIM serial number.
These apps send identifiers and ad IDs to the domain names of various advertising services. The Android Advertising ID prohibits the advertising identifier from being associated with personally identifiable information or any permanent device identifier (eg, SSAID, MAC address, IMEI, etc.) without the user’s explicit permission.
Popular apps that violate this policy include Clean Master, Subway Surfers, Flipboard, My Talking Tom, Temple Run 2, and Angry Birds Classic. These applications have been installed more than 100 million times.
Google issued a statement saying it will take action on it. “We take these issues very seriously. Combining Ad ID with device identifiers for the purpose of ads personalization is strictly forbidden. We’re constantly reviewing apps — including those listed in the researcher’s report — and will take action when they do not comply with our policies.“