This is my first post on the site and I do apologize if it seems out of place. I just thought that since the site is sharing it's musical knowledge with me, I would offer up my insight and experience into the SPAM issue.
One thing I noticed when I signed up is that the GT site/forum registration system is wide open. If there are bogus accounts being created for spamming, my educated and experienced guess is that the lack of "human factor authentication" is a large part of the cause.
Having an open system such as how GT is currently configured allows bots to register and post. How they do it exactly, I can't say as I have never reverse engineered a spam bot before, I just know that they can be programmed to find and fill in known fields, fields which all systems like v Bulletin for example, have.
To Address a post made by Kevin...
The way these bots usually work is by tagging the root domain, in this case guitartricks.com. The problem with moving the board is that you have to link to it somehow from the main site without being to complicated. The second you link to it with a hyperlink, anywhere from the root domain, the spam bots, because they read source code and not rendered code, will find it again and regardless of where you put it... they will access it and spam it again.
I implement and maintain content management systems for small businesses and one thing I have found, especially with any widely used system such as a content management system or forum application, is that SPAM in general can be reduced by doing one or both of two things...
1. - implement a system where the [U]USER[/U] has to verify their email account by clicking a link or entering a code. Based on experience with at least one of my sites that gets several bogus sign ups a day, most SPAM bots and automated systems can't follow email instructions to click a link or enter a code as far as I know so the bogus account they create to be able to post doesn't get approved...no approval, no ability to post.
2. Implement a Captcha system and make users enter the characters they see in the box. SPAM bots can't read or type...yet...so this is usually quite effective. Care needs to be taken though to have an audible option available or make the characters easy enough to see for people with vision issues. It isn't the complexity of the characters that makes Captcha effective, it's the fact that spam bots can't see picture content... just a gif/jpg/png file.
Generally if you explain to people WHY you do something and how it BENEFITS them. they won't have a problem with the extra step.
Just my two cents in an area where I have some experience.
All the best and keep up the AMAZING work!
G.