Greece, Ashley Madison and good cities.

The Greek Prime Minister Alexis Tsipras calling a surprise election for next month; personal data from the infidelity Ashley Madison being leaked onto the dark web; and the results of the Economist's Liveable Cities survey - showing European cities are dropping because of 'instability'. Issues that were in the business news headlines this week, analysed by Dominic Laurie, Robert Armstrong head of the Lex column at the Financial Times and Charles Forelle, from the Wall Street Journal in London.