Spam accounts come every so often and when they do, they can be quite a nuisance (especially if the spam account is live). If it is possible, I suggest creating a tool/page for moderators only to review all new users before they are able to post. Other than verifying their email, there should be a randomized question they will need to answer. We do this at the forum I moderate and it's surprising how many bots and spammers we get. This is extremely helpful when no one is around at the moment. It only takes minutes for spammers to cause hours of work cleaning their crap up.