Is eves dropping illegal? Who said it?

I am from India and make international calls to my family. I have no problems if a NSA agent eves drop on my call and listens to what I say. If this action makes me and my family in United States and outside safer I should infact be more appreciative. Infact I commend and salute George Bush and his government to be not a reactionary government. I like his proactive actions and him making the safety of his people his top priority. As someone living in US - American or non; why should we be concerned if Bush engaged a judicial branch to order terrorist surveillance? Even if he did, would he have told the rest of the country about it? I guess not. All it matters to us is if his actions were in good faith. I am from India - world's largest democracy and I know what civil liberties mean. But when it comes to the pertinent danger, you got to do what you got to do. I wish I had a voting right in US otherwise Bush would have gotten one more.