http://blog.mozilla.com/addons/2011/08/11/strengthening-user-control-of-add-ons/Add-ons installed by third party programs are now disabled by default
Damn straight. Firefox was getting to the point that IE was, where every program will install a new toolbar or change your search shit without your specific permission.
Just another platform hitting the pitfalls of getting too mainstream (I'm looking at you, OSX).