Director of National Intelligence James R. Clapper has put out a press release about all this PRISM stuff. In short: 'a lot of this stuff isn't accurate but I can't correct you because it's classified.'
...the surveillance activities published in The Guardian and The Washington Post are lawful and conducted under authorities widely known and discussed
I am fed up with people excusing this because it is lawful. Yeah, so what. In the US, we have had countless laws that eventually were overturned because they were unconstitutional. Just because this surveillance is lawful does not make it right. The events leading to this being lawful were mistakes, but it is not too late to fix this.