Is this the thread you were talking about?

http://www.ball-pythons.net/forums/s...ad.php?t=33693

This doesnt mean importation is without some still controversial ecological risks......the subject is a complicated one, but importation of ball pythons may be more risky to species here than the species in Africa....

"Results of the risk-assessment models indicate that species including boa constrictors (Boa constrictor), ball pythons (Python regius), and reticulated pythons (P. reticulatus) may pose particularly high risks as potentially invasive species"

 An ecological risk assessment of nonnative boas and pythons as potentially invasive species in the United States.
Risk Anal. 2005 Jun;25(3):753-66.

I have this paper.....but have yet to read it seriously.