The United States Government established a prison camp in Guantanamo Bay to prosecute detainees for war crimes. Glenn Talbot considered Phil Coulson a criminal deserving of being imprisoned there, and let Coulson himself know that when S.H.I.E.L.D. tried to protect Talbot and his family from an impending attack by Carl Creel.
Also, Carson Wolf spent some time in Guanatanamo Bay. When Frank Castle captured him he set himself free and said Castle that his tortures didn't work out.