My bad. Those 900 or so errors were for one quarter. The whole year is 2776, with 2012Q1 being the worst. Also, the trend is increasing.
Of which, 1,904 (2/3) involved cases in which a foreigner whose cellphone was being wiretapped entered the United States, where court warrants are required for most eavesdropping. A spike in such problems in a single quarter, the report said, could be because of Chinese citizens visiting friends and family for the Chinese Lunar New Year holiday. “Roamer incidents are largely unpreventable, even with good target awareness and traffic review, since target travel activities are often unannounced and not easily predicted,” the report says.
I think this is an important point to keep in mind, although that still leaves approximately 900 "real" errors.