Many clues but Homeland Security Dept is clueless.

The terrorist (and only the Politically Correct would call him "alleged") was a Nigerian (a smuggling center ), a Muslim-named passenger, who paid cash for his plane ticket (probably one-way ), had no checked baggage, was on a warning list, had his own father report him to the U.S. Embassy in Nigeria as a potential terrorist, had an expensive apartment in London's West End but was denied re-entry to Britain... That he was cleared to fly out of Amsterdam by U.S. Homeland Security is astounding and a travesty. Homeland Security did essentially nothing to thwart this attempt and only dumb luck and the quick reaction of passengers avoided tragedy. The President was not informed until three hours after the fact although news agencies reported it earlier.The incident didn't interfere with Obama"s golf today in Hawaii.
The "beefed up" security seems stupid and beside the point. The idea of stipulating that plane passengers will henceforth not be allowed to leave their seats, have anything on their laps, or access their overhead luggage DURING THE LAST HOUR BEFORE LANDING. What about one hour plus one minute? The Xmas bomber was seated and did none of the things prohibited henceforward.
The only likely prevention mechanism that can work in most cases is to target the individuals themselves with both profiling and behavioral screening modalities. Left-wing opposition on the basis of privacy and political correctness will have to yield or those people will have to take responsibility for what happens.