Whenever I'm browsing porn, there are eventually advertisements that show this (safe for work) page (WARNING: you might not be able to close it).
The page claims you did something illegal, and threatens you, saying you need to pay money to avoid going to jail. Or something like that.
How can I close pages like this? I've had this issue in multiple versions of Firefox. Right now I'm on 26.0. How can I close it without simply killing the Firefox process?
Note: The plugins Adblock or NoScript might prevent this, but I don't use those. I would like to be able to close a page without downloading a separate plugin for it.