Users of Facebook have reacted angrily to a "creepy" experiment carried out by the social network and two American universities to manipulate their emotions. The US technology giant secretly altered almost 700,000 users' news feeds to study the impact of "emotional contagion".
It tinkered with the algorithm controlling users' feeds to find out what effect it had on their moods in January 2012.
The aim of the government-sponsored study was to see whether positive or negative words in messages would lead to positive or negative content in status updates.
More top news
President Trump's administration have reinstated a likeness of Winston Churchill to the White House's most famous room.
Data-selling companies trade personal addresses and phone numbers for as little as 4p per record, a watchdog has warned.
A bitterly cold airmass covers the UK this weekend.