From the AP:

Scores of illegal aliens working as cooks, laborers, janitors, even foreign-language instructors have been seized at military bases around the country in the past year, raising concerns in some quarters about security and troop safety.

I don't know exactly how to parse the "some quarters" bit. Shouldn't everyone be concerned about this?

The aliens did not work directly for the military but for private contractors, as part of a large-scale effort by the Pentagon to outsource many routine rear-echelon jobs and free up the troops to concentrate on waging war.

Some worry that this fast-growing practice could make U.S. military installations more vulnerable to security breaches...

I don't know if this started under Clinton, but I'd imagine it's accelerated under Bush. "Some quarters" still think of the latter as our Homeland Security President.

The rest of the article lists some of the recent arrests, and I think all of them have been previously discussed in this category.