Facebook's Zuckerberg defends decision on encryption

SAN FRANCISCO Oct 3 (Reuters) - Facebook Inc Chief Executive Officer Mark Zuckerberg defended his decision to encrypt the company's messaging services on Thursday, despite concerns about its impact on child exploitation and other criminal activity.

Zuckerberg, speaking in a livestreamed version of the company's weekly internal Q&A session, said child exploitation risks weighed "most heavily" on him when he was making the decision and pledged steps to minimize harm.

The United States and allies signed an open letter earlier on Thursday calling for Facebook to suspend its encryption plan, saying it would hinder the fight against child abuse and terrorism. (Reporting by Katie Paul; Editing by Kim Coghill)