In the US and Britain, the private lives of public figures have become fair games for reporters, from supermarket tabloids to the New York Times, but in France, it's different. Now, the arrest of Dominique Strauss-Kahn on sex charges is challenging the assumption that powerful figures should be entitled to privacy. The immensely powerful head of the International Monetary Fund was the leading candidate to challenge Nicolas Sarkozy for the presidency of France, but allegations by a hotel maid have reduced him to incarceration in a New York jail cell. Elaine Sciolino reports from Paris for the New York Times.