Block extremists from uploading content, says home secretary

Extremists should be prevented from being able to post content to sites including Facebook and Twitter, the UK Home Secretary Amber Rudd has told the BBC.

The minister called for the wider adoption of auto-blocking measures ahead of a meeting in San Francisco with several of the largest tech companies. The forum will discuss ways to curb the spread of terrorist propaganda online.

The BBC's North America technology reporter Dave Lee reports.