Hmmm...it's obvious, but only in the way that circular logic is obvious to the one in the circle...Your claim that the U.S. government is saying that these companies are involved is not what I've seen (though I admit I may not have read every article on this). What the U.S. government has said is:
1) The executive branch is allowed to conduct legislatively and judicially approved surveillance and some of this surveillance is in coordination with communication companies.
2) The recent reporting on the NSA has contained several inaccuracies
I haven't seen any tacit admission of PRISM. If you want to argue that the president admitted to the program by not outright denying it (in this press conference, for example: http://www.whitehouse.gov/the-press-office/2013/06/07/statem...)...well, that again is a questionable standard of judgment, and one that is vulnerable to false positives.
You don't have a smoking gun here. You have, so far, 4 PowerPoint slides of a heavily-redacted 41-slide presentation. You have the opinion of the career intelligence officer who leaked those slides. And you have the two strongly worded denials of Google and Facebook. Note: this does not mean that the companies aren't just outright lying, which is always still a possibility. But I'm saying, from what we know so far, what has been actually said is kind of what I would expect them to say if they were telling the truth (admittedly, I may not have a very creative mind).