Its name may sound soft and comforting. But the Children's Investment Fund, a London-based hedge fund better known as TCI, is more like a pebble in the shoe of Europe Inc. Just ask ABN Amro ( ABN ). Under assault from dissident shareholders led by TCI, the Dutch bank confirmed on Mar. 20 that it is in talks to join Barclays PLC ( BCS ) in a potential $80 billion deal that would be Europe's biggest-ever cross-border banking merger; ABN Amro had been seeking a suitor to fend off TCI, which owns about 1% of the bank's stock.