So your "guess" is based on supposition, right? You don't know that the NSA doesn't have hard evidence, you suppose they do not because they have not shown it to you. What do you "suppose" internet logs would show? Do you really think that every movie or download from one system to another is archived? Having seen logs kept by credit card processors, banks, telephone companies...I can tell you that they may keep the metadata...that from IP address to IP address a file was sent and it was 5gb at a given date and time. Keeping content would be impossible. One other item...would the NSA reveal how much they actually capture?