Janet Napolitano admits terrorists cross U.S.-Mexico border "from time to time"

The video below shows Rep Ron Barber (Democratic Party of Arizona) asking Janet Napolitano of the Department of Homeland Security if it's true that there's "material evidence of the presence of terrorists along our southern border". Napolitano responds (via this):

"With respect, there have been - and the Ababziar matter would be one I would refer to that's currently being adjudicated in the criminal courts - from time to time, and we are constantly working against different and evolving threats involving various terrorist groups and various ways they may seek to enter the country.

What I can tell you, however, is that that southern border - the U.S.-Mexico border - is heavily, heavily staffed at record amounts of manpower, materiel, infrastructure and the like, and we are constantly making sure we're doing all we can to make that border as safe as possible."

For those not watching the video, it's clear from the video that the "there have been" part is meant in the sense of, "yes, there have been from time to time such incidents".

To some extent, Barber's question demonstrate ignorance of a situation that's been known for years; see immigration terrorism, for instance Chapter 3 of the 9/11 Commission Staff Report discussed instances of terrorists crossing the border or trying to do so. But, at least Napolitano's admission will help discredit those who think we could reduce border protection.

8/22/12 UPDATE: The previous video (ID ejzp_OQbgYg) was deleted. I cached the new version of the same video.