Browsers extensions are great as they enhance the usability and your experience with your browser. However, there are some extensions out there that will actually do the opposite. This seems to be a bigger problem for Chrome but there are a couple known ‘spying’ extensions in Firefox. These ‘evil’ extensions may track you or as in the case with Scott Hanselman inject ads into sites you are viewing. My perspective on JavaScript-based browser extensions has been far too naïve until this point. We were all burned by bad toolbars or evil ActiveX add-ons in the past, so when I run IE I run it with…