Here's a(nother) case where the actual title of the article doesn't reflect what the article itself says. In the article, it says the senators say they "have seen no evidence", not that no evidence exists.
God may exist, we cannot say. Cosmologists are not looking for God, and so the fact they have not discovered God means little. WMD don't exist in Iraq because it was a lie ginned up to allow us to go to war. It doesn't matter what weapons inspectors find - the point wasn't WMD but the reaction to the inspections programme.
A secret collection of mass meta-data collection being examined by people without security clearance is unlikely to find any benefit because no-one is going to tell them what happens with the data. "We see no evidence of benefit" could mean "there is no benefit, and thus we haven't seen any evidence" or it could mean "there is plenty of benefit, but that's all secret, and no-one will tell us about it, and thus we've seen no evidence of benefit".
> Engage brain before opening mouth.
That makes you sound like a bit of a dick. Just saying.
> A secret collection of mass meta-data collection being examined by people without security clearance is unlikely to find any benefit because no-one is going to tell them what happens with the data. "We see no evidence of benefit" could mean "there is no benefit, and thus we haven't seen any evidence" or it could mean "there is plenty of benefit, but that's all secret, and no-one will tell us about it, and thus we've seen no evidence of benefit".
I'm sure you are aware but Sen. Wyden is on the Select Committee on Intelligence. He is hardly a random guy with no security clearance. If he hasn't seen any evidence that the bulk surveillance has any benefit, then the NSA is withholding critical information from the people that are supposed to be performing oversight over them.
Obviously hyperbolic titles get more clicks.