Below is flight info on NW17 JFK-NRT. It was delayed for 3 hours and 20 minutes "due to security requirements." Does anyone know what this exactly means? I've seen this twice already. Is this just a rare occurence?

I'm about to buy a consolidator ticket for JFK-NRT-MNL in December and don't want to get stuck in NRT missing my connection.

- Pat

JFK 1445 1805 28SEP B28 747-400 NRT 1735 2049 E 29SEP NONE NRT
DELAYED DUE TO SECURITY REQUIREMENTS
NRT 1855 29SEP NONE 747-200 HKG 2235 2209 E 29SEP NONE HKG