Charities Tap Skills of Jobless Professionals

The glut of laid-off volunteers has forced Taproot to stop all marketing and start turning away applicants, Hurst said.

"Can you imagine working for all those years and then offering your services for free only to be told, 'Thanks, but no thanks?' " Hurst said.

"There needs to be some level of investment on the philanthropic and government side so nonprofits can leverage all this surplus of human capital," he said.