At some point, we may need to harden this forum against bots. I have noticed that when clicking on guests on the home page the IP addresses are often only different in the last quad of numbers, with the first three being all the same. That is not a good sign.
There is a setting that requires all guests to login to access the forum. That stops non-members from viewing. That's not the best plan. I found a setting that is specific to each separate internal board which allows only members or staff to create threads or post replies. This should stop guests from posting and require them to register.