I thoroughly recommend installing NoScript. I've set it to only trust first-party-domain scripts and those from a few hand-picked sites. This does occasionally

I thoroughly recommend installing NoScript. I've set it to only trust first-party-domain scripts and those from a few hand-picked sites. This does occasionally mean I'm confronted by a broken site or feature, but all I have to do is look at the list and work out what's missing. It's usually an obvious CDN.