A key Republican senator charged Wednesday that the administration’s vaunted data mining project, which has prompted fears that millions of phone calls are being stored, is so poorly run and collects so little info that it’s practically worthless.

Less than a day after the administration gave the full Senate a secret briefing on its domestic surveillance program targeting terrorists, Sen. Bob Corker of Tennessee said he was “shocked” at how bad the program is and how little it collects that Americans instead should be worried that it isn’t protecting them against attack — not spying on their phones.