A Walpole nonprofit, largely funded by the federal government, is inadvertently providing child pornographers, drug dealers, and other criminals around the world with software that allows them to remain anonymous on the Internet. The little-known company, Tor Project Inc., says its free program is designed to help people protect themselves from Internet surveillance. Legitimate users include those speaking out against oppressive political regimes in other countries, corporate whistleblowers, law enforcement officials, and domestic abuse victims.