(Reuters) - Bank of America Corp said in a filing on Wednesday that its participation in government stimulus programs like the Paycheck Protection Program (PPP) and processing unemployment insurance has led to operational losses. The filing did not provide details of the scale of the losses. U.S. banks have listed their involvement in stimulus programs that were part of the CARES Act as a risk factor after muddled guidelines and sometimes glitchy implementation opened them up to legal and reputational risk.