This is baloney. Communication networks do have flaws, and the flaws can be exploited. But communication networks are not monolithic: different vendors' equipment have different flaws. It would be devilishly hard to mount an attack on a sufficient number of vulnerabilities at the same time. Our NSA might be able to bring down communications in, say, Iraq. But Al Quaida has no practical chance of causing more than one or two U.S. networks to have a temporary outage. Europe's Internet certainly did not fail when KPNQuest was unplugged. If we can survive Bernie Ebbers, Al Quaida hAx0rz have no chance.
What this is is a distraction from serious vulnerabilities like a bioweapon attack or a SAM attack on airliners.
...another SAM attack on airliners.