Mobile apps own databases of billions of phone numbers

Several mobile apps have large databases that store the phone numbers of smartphone users. Some are even said to contain billions of songs, according to a study.

Applications Truecaller, Sync.me and CM Security, among others, have such large databases, the BBC reports after research. It is not clear exactly how many phone numbers they have, but the British broadcaster is talking about an app that is said to have stored more than two billion numbers, while there is also an app that has more than a billion numbers in the database. In the investigation, the BBC found, among other things, the telephone numbers of several well-known persons.

The existence of the databases with telephone numbers raises privacy questions. Many of the apps studied do not ask for permission to store the data. Truecaller said in a response to the BBC that it does not break European privacy rules, but that was not substantiated by the software maker.

Some time ago, Huawei announced that it will include Truecaller as standard on its smartphones. The app looks at the phone number for incoming calls, and searches in its database to whom that number belongs. It is not clear why other apps, such as CM Security, also have such large databases.