Just run a marketing forum http://www.webmasterstage.com Everything goes smoothly before so many spammers come. As you can see those names showed on Currently Active users,Many odd member names show up as txpfolrm,uedvuler,uggbootsjo,vtmqhlkh,ymnflgvd,ypuwlshfjvvp,zoscvpdseyg.... Obviously, they are spammers. Have added solvemedia captcha before, then keycaptcha now. Captcha seems not be able to stop them for they are real humans?? Any ideas? thanks.
We too had a very same problem with our forum which runs in MyBB. Thankgod there is a plugin for Mybb using this website http://www.stopforumspam.com/ After it spamming bots stoped 100%. Dont know if there is a mod similar to it in vB. If so go for it, Good luck