"I was worried about my staff - would they all get to work safely? - I was worried about my staff and, yes, I was worried about what the political and legislative response might be.
"As so often when something really terrible happens an obvious, instinctive cry goes up: 'Prime Minister, Home Secretary, what are you going to do?'
"What happened afterwards should give us some cause for optimism. Rights and freedoms are on the political landscape and there is some growing sense that getting rid of freedom is not the best way to fight terrorism."
Watch Shami's story on More4 News.
Shami Chakrabarti is director of the civil rights organisation Liberty.