“[Rogers and Romanoff have booted up an old computer in an abandoned WWII S.H.I.E.L.D base for information... and discover that the computer AI is Dr. Arnim Zola's preserved consciousness] Steve: How did you get here? Dr. Arnim Zola: Invited. Natasha: It was Operation Paperclip after World War II. S.…”
— Christopher Markus, Stephen McFeely, Natasha Romanoff / Black Widow, Scarlett Johansson, imdb.com