Washington, Jan 4 : Top-flight technology more sophisticated than Facebook and Google helped stop David Headley, charged with plotting 26/11 attacks, from carrying out more strikes, according to a top US official.

The US government's counter-terrorism system is using top-flight technology, President Barack Obama's Homeland Security and Counter-terrorism adviser John Brennan asserted Sunday on ABC, citing the Headley case.

"Well, in fact, we do have the sophistication and power of Facebook, and well beyond that," he said when asked: "In the era of Google, why does the US intelligence community not have the sophistication and power of Facebook?"

"That's why we were able to stop Najibullah Zazi, David Headley, other individuals from carrying out attacks, because we were able to do that on a regular basis," Brennan said.

"In this one instance, the system didn't work. There were some human errors; there were some lapses. We need to strengthen it," Brennan said when asked about the apparent failure to predict the attempted Christmas Day bombing of a US airliner.

Headley, arrested in October, is charged with scouting targets for Mumbai terror attacks. Zazi, an Afghan citizen, was arrested in September 2009 for being part of a US Al Qaeda group accused of planning to carry out acts of terrorism against the US.

"Clearly, the system didn't work on that day because (Nigerian suspect) Abdulmutallab should never have gotten onto that plane with those explosives. You know, every other day the system has worked so far this year. We've been able to thwart attempts by Mr. Najibullah Zazi, David Headley, and others," Brennan said on an NBC talk show.

Asked how does this kind of thing happen despite multiple in-points into the system, he said: "I think that we have been to that place many times with the disruption of plots that are taking place every day, whether it's overseas or here. Mr. Zazi, Mr. Headley, others, those dots did come to the surface."

"What we need to do, though, is to be able to do that every day. But the system is working; it's just not working as well as it needs to constantly." (IANS)