Set your Flash plug-in to “Ask To Activate” on all your browsers. In addition to the security hazards, Flash uses cookies that are very hard to control, and uses up bandwidth downloading content you generally don’t want to see anyway.
One immediate problem, alas, with this move to HTML5 is that HTML5 videos download and play automatically, and I haven’t figured out an easy way to control that (in FireFox, it appears that a lot of about:config hacking is needed).
“One immediate problem, alas, with this move to HTML5 is that HTML5 videos download and play automatically, and I haven’t figured out an easy way to control that (in FireFox, it appears that a lot of about:config hacking is needed).”
Try this:
NoScript Add-on for Firefox
https://addons.mozilla.org/en-US/firefox/addon/noscript/