Twitter has warned of unusual activity from China and Saudi Arabia related to a bug in a help form. The bug - discovered on 15 November and fixed the day after - could have revealed the country code of users' phone numbers or if their account was locked, the company said.
Facebook has revealed that a software bug exposed the photos of up to 6.8 million users, including pictures they had not posted. It made the announcement a day after hosting its pop-up privacy experience It's Your Facebook in New York's Bryant Park.