My very pro-Bush administration does not believe that the US DOJ, INS, and other groups have detained U.S. Citizens, green-card holders, and non-citizens alike since September 11th. Or, rather, if this has happened, it is in very select few instances.

It seems easy to find info surrounding this problem (New York Times, ACLU website, NYCLU website). I have found it difficult to find the actual numbers (or estimates) of each group that are currently or have been detained.

How many people are detained in detention centers with no "legal" grounds for their being there? How many are US citizens?