Offtopic, maybe: I've taken to blocking all JavaScript using NoScript. I don't want random strangers from the Internet running programs on my computer. Besides, disabling JavaScript has made my browser so fast it's not even funny. Pages load instantly, runaway scripts no longer take 25% CPU, pages don't try to autorefresh every 5 seconds. And, of course, no Google or FB ads.
The downside to NoScript (as someone who's been using it for a while), is when you do find a site you want to visit, which for whatever reason requires its scripts to function properly, you're often left at the menu, wondering which of the half a dozen or more scripts you actually need to allow (some advertising / metrics companies can be easily spotted by domain, but often you've got the original site, maybe one or two static content domains, perhaps a CDN.) It gets to be a hassle