Yeah, my point is, we don't really know what the scope is -- we have Snowden's word and some slides that mention direct access to servers. But the engineers who worked at the companies and performed the integrations know and probably have evidence if it was just standing up a box they scp'd data to manually upon request, or a more elaborate automated system. If some of those people would step forward with evidence, we could could confirm or refute Snowden's claims.
But the minute some Google (or Facebook, etc) engineer mentions some slight detail about how that access works, you will have half the Internet trying to break it.
Although that would be kinda fun....
