The Denver Three have decided to sue. But who? They're not sure.

"We want to know who this person is, and who trained them, because we're going to sue" both the man and his trainers, said Dan Recht, a lawyer representing Alex Young, Karen Bauer and Leslie Weise.

The Secret Service has launched an independent investiation into the ouster of the three Denver activists from a Bush social security speech a few months ago. But they determined his identity shortly after the event when they interviewed him. The problm is, they won't share the information with The Denver Three or their lawyers. The Secret Service told Recht that the man was a Republican Party staffer who admitted he bounced the three solely because they arrived in a car with a "No more blood for oil" bumper sticker. The Secret Service and the White House, which says the man was a volunteer, have refused to reveal his name. The White House sent out an advance team for the event. Bob Beauprez, at whose office the tickets for the event were picked up, said he had no security people around, it was the President's deal. Rep. Mark Udall has asked for an investigaton by the Secret Service. Sen. Ken Salazar has asked the Inspector General's Office to get invoved. He is demanding has demanded the name of the volunteer from the Secret Service and details of of steps taken by the agency to ascertain whether any laws were violated when the agency attejwhat the agency did to determine if he unlawfully posed as a law enforcement official.