Firefox users on Windows with old versions of Adobe Reader, Adobe Flash, and Microsoft Silverlight will be forced to update old versions. Firefox 17 is now in beta and with it is a very cool feature, click-to-play plugins. Mozilla is still working on implementing the controls, which would allow you to block all plugins by default and then pick where you want them to run. The main motivation behind this plugin is to prevent users’ systems against drive-by attacks that target vulnerable plugins.
Source: https://thehackernews.com/2012/10/firefox-17-beta-released-with-click-to.html