They are not saying it. But they are doing it. The mortgage market downturn has already caused some online lenders to let some employees go, even though most are mum about their layoff plans. E-Trade two weeks ago laid off 163 phone-service representatives. GMAC-RFC’s DiTech.com axed an undisclosed number of employees. Countrywide, which has one of the industry’s most robust web sites, reportedly has shed 500 jobs since July.