According to my wife, Firefox is currently having trouble publishing an update that will successfully patch a security risk due to what embedded Java can do.
Time to disable Java in Firefox, at least for a while.
This issue prompted me to read a bit more about Ubuntu security, which recommended three Firefox add-ons that would benefit people who use the browser on any operating system.
Two I already use: NoScript and Adblock Plus. I found out there is a third important one: BetterPrivacy, which blocks parts of Flash files that act like cookies (called LSOs).
Installing BetterPrivacy was easy and took only a few minutes. After the install I needed to go to its option in the Tools menu, tell it which LSOs I do not want deleted, and then tell it to delete and protect from the rest.