"So, you are saying that known suspected terrorist numbers dialed from the US aren't checked..."
No, I am saying the warrantless NSA tappings are being done by incoming calls from other countries.
They are obtaining warrants from the judicial branch to conduct what I've quoted from you above.
In the case of a misdial, a warrant can be easily issued based on the presumption that the number was dialed deliberately. If that presumption can not be made, then any dialing of a known suspected terrorist must be presumed to be misdialed.
You can't have it one way and not the other.