Jane and others,
Thanks for being our eyes and ears on this. I know it's frustrating that spam could and would come through a non-profit group that nearly all of us have found while simply looking for information and support. Unfortunately, these guys are ruthless, and we do our best to take care of them as soon as we're made aware of the problem.
I just want to remind everyone that these spammers (or anyone else, for that matter) CANNOT see your e-mail address unless you reply to them. So long as you do not reply to spammers, they do not have your e-mail address, personal info, etc. Once we lock their account they can't send anymore spam through the site - rendering them harmless, so long as you've not replied to any e-mail from them.
Thanks again for your help and patience with this!