An International Computer Science Institute research cited by CNET shows that roughly 17,000 Android mobile apps have been collecting identifying information from at least 100 million devices. Some popular apps include Angry Birds Classic, Audiobooks by Audible, and Flipboard.
Google allows app developers to collect the Advertising ID — a unique, user-resettable ID for advertising — of users but recommends that developers "ensure the identifier cannot be connected to personally identifiable information (PII) and avoid bridging Advertising ID resets." According to the International Computer Science Institute's research, however, less than a third of the 17,000 apps solely collected Advertising ID data. Instead, a majority of these apps collected information from other identifiers on Android devices that are difficult or impossible to change, packaging and selling this information to advertising services.
Google tells CNET it has investigated the report and has taken action on some apps.
"We take these issues very seriously," a Google spokesperson said in a statement to CNET. "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."