A quick and simple modification for RavenNuke™ v2.5; which adds an additional layer of protection against unwanted Profile and Signature Spam links. New users can still enter their website URL and Signatures, but they will not display to visitors (or search engines) until the user has 5 or more forum posts. Since most spammers won't take the time to write 5 relevant posts, it works as a preventative measure; requiring too much work for the profile spammer to make it worth their time. This also allows site owners to still give "link juice" to respected members while casting the unwanted spammers aside.

Spammers are also using spam profiles as yet another avenue to generate webspam on otherwise good domains. They scour the web for opportunities to get their links, redirects, and malware to users. They use your site because it's no cost to them and they hope to piggyback off your good reputation. Official Google Webmaster Central Blog

Obviously, this is only intended for sites with an active Forums module, so this is not the perfect solution for every site. If you do not use the Forums module, note that there there are options for controlling which fields are viewable in Your Account; in the User ACP. While these edits are specifically done for RavenNuke™ v2.5; with the exception of the Your Account edit, they would probably work for other phpbb-to-nuke installations, although may require tweaking and are untested.

If you have any issues, comments, or questions, please see this forum thread.

To help further combat spam and undesirable access, also be sure to check out nukeSPAM by nukeSEO and Site Guardian by Code Authors