Good to see demonstrations, the mas surveillance program is beyond madness. As Snowden said, many cases in which this data is used are actually abuses. Sadly many NSA officers go by the saying 'see no evil, hear no evil, speak no evil'. I suggest all of you to use encryption for your data.
The amount of data that the NSA gathers, makes it so even if they do find data that could prevent an attack, they would probably not realize it and would not be able to act on it.
Even if something is encrypted, it does not mean there is no way decrypt the message/file without breaking the encryption.