I'd like to add that if you're not already running those add ons then you're inadvertently being dumb.It depends on which browser you use and which mining service the ufc is using, but it basically boils down to blocking Javascript from a set of domains.
Just google 'disable javascript bitcoin mining' along with your browser, and you should be able to find a number of options. Here is an example.
NoScript will do the trick, and there is also a filter you can use if you have AdBlock Plus.
It's like banging a hooker without wearing a condom even if you don't know that condoms are an option.