What's going on in this video?
https://www.youtube.com/watch?v=lXVqdezJf1A
Here, the ISP restricts access to all other sites but one (twitter.com) when the user's account balance is insufficient. In this video, an SSH connection is being used somehow to connect to restricted IP addresses through the ISP's proxy server.
How is all of this working? And what can be done to protect against such attacks / hacks?