@all reading this thread,
About the use of Umatrix. The issues that should be blocked are blocked as by default in the extension. Sometimes you should unblock certain red marked default items to get full functionality of a particular page (consider the risk involved and jump when you think you can leap) - the great thing about the extension is you can additionally block items on the website after you have made a decision what should be additionally blocked. Just like with NoScript you should know where and how to grant access (allow). For advanced users you get almost complete security control that way - as all scripts are also being blocked by ScriptSafe by default (allow what you need for functionality on a known potentially secure page). When in doubt report here in the forums and we will find ways to give you some full report on what security/insecurity status a page has (at that moment) to the best of our knowledge from third party cold reconnaissance scanning results. For this Avast forum page where I add this posting in this very thread unblocked is forum.avast.com with 1 cookie, 1 css, 43 images, 2 scripts (green).
Blocked by Default is the tracking from google on google-analytics dot com and 1 script from www.google-analytics.com (a script you may allow as avast uses the info for user protection info purposes, while on the other hand google sits on that very data heap). 
You want facts about in-browser security and how to bring that forward, we try to give you these facts from our years of experience as a volunteer website security analyst (with profound thanks to all here that help me achieving this, and those that do know who I mean here).
polonus