I do it with uMatrix. I usually go up to the "all sites" level and enable most everything before going through a credit card payment flow, for this reason. Sec

I do it with uMatrix. I usually go up to the "all sites" level and enable most everything before going through a credit card payment flow, for this reason. Security is only part of my motivation, though, and not the main part -- I mostly do it because it protects me by default from all the pop-up type crap that so many websites foist on you. Yes, it's a pain to un-break sites sometimes. But I resent it less than going through the equivalent pain in "privacy settings" popups, wriggling chat widgets, "ate you sure you don't want to sign up for our newsletter?" nags, etc. Websites are already broken; as long as that's true, I'd rather be in control of why.