10 things we learned this week
G4S gets hoaxed, Sainsbury's makes peace with the Germans, Tim Geithner's colourful language.

1. Someone really doesn't like G4S. An extremely sophisticated prankster launched a fake website for the security company claiming it was restating its accounts and firing its CFO.
2. Sainsbury's has made peace with the Germans. No, not Lidl & Aldi, the discounters threatening to steal its customers. Its Christmas ad, 'cynical' or 'moving' depending on your perspective, evokes the legendary Christmas truce in First World War, which was held 100 years ago.
3. Former US treasury secretary Tim Geithner has a penchant for the F word. His expletive-laden rants about Europe's treatment of Greece were leaked to the FT this week.