People live. People die. Tweets fly. Android is eating the world. Sharing too much info on social networks can be bad. The Internet, well, it just works.
Most of us understand these things at a high level. Of course people die. But mere words and concepts don't drive home the sheer magnitude of the things buzzing all around us, all the time. For some things, actually seeing the data in real-time visualizations hits you in a far more visceral way than a wall o' text ever could.
These websites will change the way you see the world. If nothing else, you'll never view your Facebook posts in the same, lighthearted way ever again.