In what would be the largest lawsuit in the history of mankind, Bank of America has threated to sue LaSalle Bank’s parent company if it fails to acquire the Chicago bank. Bank of America had a deal in place to buy LaSalle from its parent company ABN Amro, when a group of European bankers lead by the Royal Bank of Scotland stepped in with a hostile bid for the entire company. Just for some perspective on how ridiculously huge a $220 billion lawsuit is: