It is a Constitutional violation, plain as day. That's why they are having to say it was 'implied' in the authorization of force resolution or that the power is 'inherent.' Everything that specifically addresses the question says they can't do it.
It is quite sad that so many are willing to just look away.
I sent it because it clearly says that warrantless wiretaps are permissable. That deals with one aspect of this matter.
You have, I'm assuming, seen the link that deals with US citizens?