block websites with terminal

I'm trying to block websites using terminal on my Macbook. I've done this before and it worked fine. But now I'm trying to add additional sites that I want to block, and it's not working anymore. I've formatted the new lines exactly as the old. I also removed one of the sites I had blocked before and tried to add it again, but it won't work either. What's going on? The new lines are all formatted exactly the same as when this worked for me. I've followed all the formatting I've seen on various tutorials. I've flushed my cache. Nothing works.