During the last week is has become clear that there is a new wave of spambots registering on PHPFusion v6 sites. Especially sites that do not have member activation by administrators enabled may suffer from severe spamming in comments for news, photo's, custom pages, etc. It appears as if at least two different waves took place; the first possibly testing whether the bot script worked, the second doing most of the severe spamming. The first wave resulted in registrations with the name Wilfred_Detwistleton8005 and only few spam comments were left. The second wave used the name Walter_Rowbotham36c41 and I have seen sites with as few a zero spam comments, but also ones with over a hundred. Used email accounts were gmail accounts with a plausible sounding name (which did NOT reflect the chosen username) and with a few apparently random letters and numbers before @.
Deleting the bot accounts will delete all spam comments. To prevent the spamming from happening you should enable member activation by admins or upgrade to v7 for a different captcha method. Perhaps some third party mods can also prevent the spam.