Social media firms will be summoned before the Home Secretary on Thursday after it emerged the Khalid Masood sent an encrypted message via Whatsapp minutes before the Westminster attack. Amber Rudd claims efforts by firms to curb extremist content online have been inadequate. But what issues would be raised if tech firms were to open up their platforms? To find out Georgie Frost was joined by Ed Johnson-Williams, a campaigner for The Open Rights Group - which campaigns for internet privacy.
