The city of Chicago on Thursday announced it was suing Equifax for failing to notify city residents quickly after the credit-reporting agency sustained a security breach that exposed confidential information of about 143 million people.At a news conference in City Hall, Mayor Rahm Emanuel and Corporation Counsel Edward N. Siskel said that, under the city’s consumer fraud ordinance, Equifax could be liable for as much as $10,000 per resident whose data was breached per each day that resident was not notified.&ldquo …