A few weeks ago, something surprising happened: A team made up of three New York state inmates faced off against a team of three Harvard undergraduates in a debate — and the prison inmates won.

People have responded with shock, with the story going viral on Facebook and Twitter over the past week. For many people, it goes back to one question: How could prison inmates, convicted of violent crimes, beat Harvard’s debate team, the current national champions?

But this isn’t that shocking, given the prison inmates’ record: They have beaten some pretty impressive competition before, particularly debate teams from the US Military Academy at West Point and the University of Vermont.