Script Summary: completely ignore posts by users and threads started by users
most code grabbed from another script but enhanced to be able to ignore topics from certain users.
To modify, go to tools->greasemonkey->manage user scripts, then select "Zass Vbulletin Ignore" and press the "edit" button.
This will allow you to edit the script. Then modify the line that looks like this:
var ignore_threads_from = ["Fourthmeal", "Dave Thomas"];
to ignore threads from whoever you want. So for example, if you want to ignore threads from users named "Bob", "Sandy", and "Frank", you would change to
var ignore_threads_from = ["Bob", "Sandy", "Frank"];