A few months ago there was quite a discussion on this list of an email sent from Bill Louw's GMail account reporting a mugging and asking for help. In April something similar happened to Deb Fallows, whose husband Jim chronicles the attack, its likely source and possible ways to prevent such hijacking in the November 2011 issue of the Atlantic Monthly: http://www.theatlantic.com/magazine/archive/2011/11/hacked/8673/
His blog has various posts on this incident and prevention strategies, e.g. http://tinyurl.com/3b2c56b
Bill Fletcher