Recently I've been getting a number of spam sign-ups on my Vbulletin forum - the usual email sort of stuff, offering pharmaceutical drugs, dating services and the like. I've been pretty quick to jump on most of them, and I have banned a number of IP addresses, but they seem to come from random ones, most likely through proxies, so it doesn't have too much effect. I would imagine that these aren't bots because they're going through the image verification... I have turned "Moderate new members" on, which means I have to approve people before they can post... are there any other steps I can take as well as/instead of this?