Social apps 'harvest smartphone contacts'

From BBC:

Twitter has admitted copying entire address books from smartphones and storing the data on its servers, often without customers' knowledge.

Access to the address book is enabled when users click on the "Find Friends" feature on smartphone apps.
Two US congressmen have written to Apple asking why the firm allows the practice on its iPhone, as it contravenes app developer guidelines.
Twitter has said it will update its privacy policy to be more explicit.
The practice came to light when an app developer in Singapore, Arun Thampi, noticed that his contacts had been copied from his iPhone address book without his consent by a social network called Path.