25 - 30 million seems about right
http://wsjclassroomedition.com/archive/05apr/econ_underground.htm
Okay they said 18-20 million in April of 2005, over 2 yrs ago.
http://www.factcheck.org/UploadedFiles/Bear_Sterns_20_million_illegal.pdf
ahhh I found the original pdf.