Saudi Arabia has recently become concerned about the security of it’s long and traditionally porous desert frontier with Iraq, across which many Saudis have traveled to seek "martyrdom" in Iraq. The border is essentially a line drawn on a map, not too long ago, by far away governments, and has no relationship to local the local people, who are mostly tribal desert Arabs used to traveling where they will over a swathe of territory that have traditionally controlled - often with force - for centuries.
Tribal fortunes largely rest on their ability to move about, to tend flocks, carry trade goods, and, not incidentally, indulge in smuggling. The Saudi government is trying to develop ways to deal with the tribes in ways that avoid upsetting them, which could drive them into the arms of the Islamists. One approach is to recruit tribal members into the forces patrolling the region, which are apparently increasingly making a distinction between "good" smuggling and "bad" - that is, looking the other way if smuggled goods are "innocent" but taking action if arms or other dangerous goods are involved. The government has also, apparently, been quietly establishing small posts along the frontier, intended to monitor traffic.