Well, since there seems to be some disagreement, maybe people can mention specific firms they know for a fact that don't use credit checks?
One guy mentioned that Scottrade <i>did</i> check your credit rating, and I can tentatively agree--when I was at the Scottrade offices, I vaguely remember one of their brokers mentioning it in the passing. That's one of the reasons I was worried about this in the first place.
But... if people here with bad credit (or those who check to see if their credit report has been queried) can confirm that their futures broker (mentioned by name) did or did not check your credit, it would be a big help.
Data file is still availible, for those who are interested and willing to help. By the way, I'm leaving town Sunday morning so if you reply later than that I won't be able to send you the link until I get back next Saturday night.
And for those who are helping me merely out of the kindness of their heart, I sincerely thank you as well.