Why are all of the plug-ins blocked on pages I used to go to to watch stuff?

I just returned from a trip tp Elsewhere, Canada. When I returned home every page that I opened to watch stuff had a "Plug-ins Blocked" on the small window on my on my Macbook monitor. Some of these pages want me to install the "latest version of Adobe Flash Player". Does this have ADOBE paint all over it. Gee! I can't even watch the CBC News on my laptop.