Top intelligence agency lawyers said on Thursday that the U.S. government can do more to increase the transparency of surveillance activities that have drawn rebukes from the technology industry and the public at large after the revelations by former National Security Agency contractor Edward Snowden.

Although they can’t reveal all their secrets, U.S. spy agencies can provide information that helps the public better understand their authorities while also protecting national security, general counsel Rajesh De of the NSA and Robert Litt of the Office of the Director of National Intelligence said. They were speaking at an American Bar Association conference on national security law in Washington.