Justin has been having trouble printing International eBay labels for the Mac, so he downloaded a PDF browser plugin to get around the issue. Now that the issue has been fixed, he can't get the plugin to go away.
Joan likes to watch TV on her Mac, but now she's getting a message about a blocked plugin. Leo says that Apple keeps a list of "unsafe" programs on Joan's Mac and all she needs to do is download and install the new Flash player. Once that's done, Apple will view it as safe again.