Sul nuovo obbligo di attivazione manuale dei filmati Flash e più in generale degli "active content" (Shockwave, Acrobat, Media Player, etc) presenti nelle pagine web.
Dal sito Adobe.com

Preparing Websites with Active Content for Announced Browser Changes
Many of you have read about the announced changes in Microsoft Internet Explorer. You may have some questions about what's going to happen to your websites that use embedded ("active") content and applications. Active content can include Macromedia Flash, Shockwave, or Adobe Acrobat files. You are probably starting to consider what you're going to do to be prepared...

E dal sito microsoft

Activating ActiveX Controls
Users cannot directly interact with Microsoft ActiveX controls loaded by the APPLET, EMBED, or OBJECT elements. Users can interact with such controls after activating their user interfaces. This topic describes how Microsoft Internet Explorer handles ActiveX controls, shows how to load ActiveX controls so their interfaces are activated, and describes the impact of this behavior on accessibility tools and applications hosting the WebBrowser Control...