Two GOP lawmakers charge that the Obama administration violated a law requiring the White House to give Congress a month's notice before transferring or releasing Gitmo captivies. From the AP via Business Insider:

The White House said it moved as quickly as possible given the opportunity that arose to secure Bergdahl's release. Citing "these unique and exigent circumstances," the White House said a decision was made to go ahead with the transfer despite the legal requirement of 30 days advance notice to Congress.

Source: Reason.com

"To take from one, because it is thought his own industry and that of his fathers has acquired too much, in order to spare to others, who, or whose fathers, have not exercised equal industry and skill, is to violate arbitrarily the first principle of association, the guarantee to everyone the free exercise of his industry and the fruits acquired by it." --Thomas Jefferson