Meh, I'm involved in a lot of traffic shaping, management at work so this is something which I'm rather controversial on compared to the general census. Although, it's good to have discussion.
You'd be surprised how many ISPs have the potential capability for what the NSA is doing. For example, I can filter traffic by user, website, activity. For example see the total bandwidth being used for XBL, P2P activity for example and look at each user using those services.
What I want to know is how the NSA is logging/collecting this data. If the NSA is somehow monitoring Tor for example, then they should flag traffic by the parameters they need and only log information which deems needs investigating. If the information is indeed nothing, it should be erased without any trace. Although, if the NSA is blanket data collecting and keeping the majority of the information pouring through, then I'm strictly against this.
In fairness though, Tor and Tails will be used more than likely by people who may be cause for national/international concern. So I can understand why they're trying to look into it.