Hi. First of all, we believe in open access and don't favour restrictive policies. Most of the staff have been part of various online communities, and we don't like having restrictions just to access content easily available on dozens of other places. It's not only inconvenient for members, but also ineffective.
We also believe that, while on the Internet, people should know how to behave and police themselves. The mere descriptions of our forum subsections should be telling enough about their nature. (This is assuming the descriptions are understood by the visitors, anyway. If someone doesn't know English well enough but takes a shot at navigating around despite not knowing what a term or description means, then what he comes across is his own responsibility.)
We can't determine the exact age of our users for sure. All we can do is take their word. Our site isn't like Google or Facebook which are included as default bookmarks on many web browsers and other applications. Someone who is visiting ASF is likely doing so out of his own will or through a search engine (which implies that he was doing a specific search) or was linked by someone else. It's unlikely an inadvertent act. In short, it's inconceivable to hold ASF responsible for what its users view.
Lastly, ASF isn't a social networking site like Twitter or Facebook. Members aren't expected to put any private information on their profile page. I understand that your concern mainly has to do with profile pages, but all the threads and posts normal members can post in are already open to public view. Also, anyone who can pass through the captcha and mail activation can have an account. Personally identifiable information, such as email and IP address, is still kept private from public view, so as long as you don't lay out your personal information on your profile, there's no difference whether it's a bot, an unregistered user, or a member accessing your page.