A few suggestions and issues:

I can't figure out how to add my own keywords. All I can do is choose from the predefined lists like "popular" etc.

The scroll bar is very faint, almost to the point where I didn't realize I could scroll and thought the UI had broken when the "replace content" box was pushed off screen by kill list selections.

On Facebook, when you replace content I see the rather logo and an "undo" button. I'd like to see a "why?" link or text description explaining what kill list was matched for that particular content to be replaced. I had a friends post, seemingly about nothing, replaced and I couldn't figure out why.