The report a while back in the NY Times on the secret CIA station located in 7 World Trade Center, claimed its primary role was to surveil UN members and staff. And its cover was the Secret Service office in the building (which also housed NYC's Emergency Operations). Couple of things on that. The building, which was only a few years old, is reported to have collapsed due to high heat of oil storage tanks, a small tank on the upper floor to serve NYC Emergency Operations, and an unsually large tank in the basement. The building owner, Larry Silverstein, who leased the WTC towers, says the basement tank was for emergency power. Period. However, while many buildings have emergency power systems, few have the size of tanks in 7 WTC. Which may indicate that the building housed a variety of operations needing uninterruptable power, and which, in turn, could explain why NYC put its emergency operations center there despite public ridicule for putting it on a high floor, of a glass walled building, next to a likely terrorist target. Moreover, it is unlikely that the purpose of the CIA station was only that made public to the Times. More likely is that the public story is a cover for what the station did. One possibility is that it engaged in communication interceptions, if not transmissions to agents as well, and could have made use of the antennas atop WTC 1, or antennas cloaked by the public antennas. Now whether bin Laden, or whoever planned the attack, knew of this, or suspected it, could enrich the speculation about why the towers were targeted. Certainly it would take no comsec genius to perform analysis of what was coming and going atop the towers, or that may have been going on under cover of the tower's emissions. All the public emissions could have been discounted and the remainder subject to detailed scrutiny. Perhaps the ordinary mujahadeen couldn't do that kind of analysis but certainly a slew of other nations could. As well as private comsec companies, of which there are dozens in NYC peddling their services to US and foreign clients. So, if the CIA was surveilling these private security companies, along with the comms of the UN members, it may well be that countersurveillance picked up the snoops and the information was peddled to assassins or used to justify engaging hit squads to take out the transgressors. Finally, oil storage tanks are required by building and fire codes to have especially durable fire-proofed enclosures, the design based on the size of the tank and any expected worse case scenario. At least this is the case when a facility is subject to municipal regulations. Which we know the WTC was not. Whether the Center's unusual vulnerability attacted the attack is a fair question. But don't expect any findings to be made public is this is the case, for that might require delving into which operations in the Center invited retaliation by those who had been attacked by them.