I came home today to find that my iMac had not gone to sleep and was extraordinarily sluggish. Coincidentally, activity monitor was loaded and showed 1 garbage news site eating almost a gig of ram and a good chunk of my CPU. I also found 3 sites laundry.reviewed.com, vacuums.reviewed.com, and laptops.reviewed.com which are running in the background and eating about half a gig of ram and about 23% of my CPU when combined. How can I effectively block these tracker sites from loading again. Is it possible to do it without adding clunky adblocking software?