[ksk]

I think you're correct in general (in terms of standards of evidence), but if we are to accept Google's claims at face value, then why would you not also accept the leaked emails as evidence of collaboration?

Specifically, this[1] email exchange:

NSA Director (Keith Alexander) to Google's CEO :-

"It was good seeing you recently after the meeting earlier this month"

"Google’s participation in refinement, engineering and deployment of the solutions will be essential."

Make of that what you will..

[1] : https://www.huffpost.com/entry/nsa-google_n_5273437

[zepto]

They are evidence of some kind of collaboration.

The problem is that evidence of collaboration doesn’t substantiate anything at all about participation in prism or any other illegal or underhanded scheme.

We know that Google does have portals to service lawful government information requests.

It’s also entirely possible that Google participated in some kind of analytics development based on their web indexing and nothing to do with private user data.

Either of these would be at least plausible explanations for these comments as “they joined prism and handed over all data to the NSA”.

Innuendo is not evidence.

[ksk]

I guess we'll have to wait for another leak to get confirmation on the exact nature of the relationship.

[zepto]

Absolutely.

But until we do, there is no evidence to support these claims.