The FBI secretly sought information last year on 3,501 U.S. citizens and legal residents from their banks and credit card, telephone and Internet companies without a court's approval, the Justice Department said Friday.

That's one out of every 85,000 people in the US (roughly). Now it wouldn't surprise me if there are 3500 people who should be checked out, but that's the whole point of FISA and the fact that they can RETROACTIVELY approve searches. National Security Letters have already been discussed here but as also discussed here they get used in areas that have nothing to do with National Security.

AOL News - FBI Investigated 3,501 People Without Warrants