Interesting comments thus far, so please humor me as I follow this line of thought:

Even if Islamic converts might stand out amongst the Catholics, how easy will it be for them to suppress their new principles of life, in order to participate in an attack?

Take this a step further and look outside the Philippines for a moment. It's a fact of life that many Overseas Filipino Workers (OFWs) work world-wide, centered on the service and hospitality industries. Would the powers-that-be in Manila be concerned at all with these networks that have spread across the world?

Not only is their purchasing power immense, OFWs have developed a very robust (although transparent) system to move money back to the PI. I curious if those networks are monitored, because it would seem that they are wide open to manipulation for nefarious means.

I'm also curious how OFWs fare when trying to navigate the post-9/11 immigration/customs/visa regulations around the world. Are they equally restrictive if the OFW is from, say, Jolo or Mindanao?

Perhaps Maxwell and Pinoyme have some insight.