[xfords.com]

i have a massive list of emails you should consider banning to help combat these spammers, seems to be these are the most common i have found signing up, i am slowly finding les and less of them now as i continue to add the emails in,

you might find these match with some of the spammers you are getting and might be worth adding to your user banning options, il post them for you and add these as they might stop some of your spammers signing up under these emails,
i guess if you allow people to sign up under gmail then you could remove that from this list, but im finding im getting more spammers from gmail than i am from hotmail,

@gmail.com @21cn.com @seorj.cn @mail.ru chongsoft.org @viagrabe.com
@adwords4u.org @anime.pp.ru @bk.ru
@fromru.com @investment-property-for-you.com @buziaczek.pl @ua.fm @dfpo.biz @inet.ua @pozitifff.com @uganska.net @inbox.lv @onlyfun.biz @hotpop.com @haos.net @mail.ru @mail333.com @mymail-in.net @mymail.net @xmail.com
@youdealonline.org @mytop-in.net @fasif.com @zsdfg.com @e-mail.com @gmail.ru @sevastopol.in @hotmail.org @gmail.org @pmrmail.com
@kremenchug.ws @email.com @gmail.net @tmail.com @gawab.com @aibolit-discounts-meds.com @tmail.net @live.ru
@hotmail.net libertyreserves.org @chongsoft.com @httpza.net