“Every now and then, there may be a mistake,” Cole said in congressional testimony.
Thats how thousands of times per year is defined,,,a mistake every now and then.
Extrapolating and/or parsing...
If 3000 is a few times, then they must be checking a vast amount of people overall in order to make 3000 erroneous wiretaps/email scans/ data mining excursions appear to be miniscule in comparison.