The nation’s cellphone networks could suffer “potentially catastrophic” cyberattacks by iPhone-wielding hackers at home and abroad if iPhone owners are permitted to legally jailbreak their shiny wireless devices — that’s what Apple claims.

“The technological protection measures were designed into the iPhone precisely to prevent these kinds of pernicious activities, and if granted, the jailbreaking exemption would open the door to them,” Apple added.

Threat Level had no idea the iPhone was so dangerous. We’re gratified that Apple locked down this potential weapon of mass disruption before hackers could unleash cybarmageddon. This also explains why Apple rejected the official Google Voice App for the iPhone this week. We thought it was because Google Voice posed a threat to AT&T’s exclusivity deal with Apple. Now we know it threatened national security.

The EFF has asked the regulators for the DMCA exemption, (.pdf) which would allow consumers to run any app on the phone, including those not authorized by Apple.

Fred von Lohmann, the EFF attorney who made the request, said Apple’s latest claims are preposterous. During a May public hearing on the issue in Palo Alto, California, he told regulators there were as many as a million unauthorized, jailbroken phones.

In an interview Tuesday, he said he suspected those phones have not been used to destroy mobile phone towers. “As far as I know, nothing like that has ever happened,” he said.

He added that, if Apple’s argument was correct, the open-source Android phone from Google on T-Mobile networks would also be a menace to society. ”This kind of theoretical threat,” von Lohmann said, “is more FUD than truth.”