No problem.
The relevant file to edit is vBulletin's include file
functions_online.php.
I'm currently running vBulletin 3.0.7, just in case things are slightly different.
In functions_online.php, find the following code (it's at the end of the very long userinfo['activity'] CASE stmt tree): Code:
Content visible to verified customers only.
Add the following code directly ABOVE that code block: Code:
Content visible to verified customers only.
Now, find the following: Code:
Content visible to verified customers only.
And add this directly below it: Code:
Content visible to verified customers only.
And, now find this code (it's at the end of the very long // Showthread CASE stmt tree): Code:
Content visible to verified customers only.
Add the following directly ABOVE that code block: Code:
Content visible to verified customers only.
That should be it. I don't remember editing any other include files, but if this doesn't do it let me know and I'll look at my other files, as well.
vbulletin.org also has a mod available (haven't tried it, so can't vouche for it) that is supposed to make additing add'l locations easier...with no file edits required, using vBulletin's admin panel (I think).
Here's the
vbulletin.org thread for the mod and the
vB3 version of the mod, as well.