I clicked on this link at work (part-time at grad-school) and now I have a "how to run a pornographic website faster" link logged in my name.
The comments here have double that, including your own use. If you were genuinely that paranoid about being "logged" for having visited a page that used the word porn (really?!) I doubt you'd be using it yourself.
I'm just saying that it could get someone into trouble.
As far as the "logging" goes, it had more to do with the word porn in the title of the page, because many content-filters just parse the title for blacklisted words.
It being common just makes it even more funny.