Jack Dorsey
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Twitter co-founder defends app and talks about new project

The chairman and co-founder of Twitter, Jack Dorsey, has been in London for the global launch of his new company 'Square'.

The free app turns a tablet or smartphone into a sales register that can be used to process payments.

He spoke to the BBC's Rory Cellan-Jones and defended Twitter against criticism including its use by terrorists and its power to end politicians' careers.

  • 21 Nov 2014
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