Steem is an open-source blockchain platform for publishing content. It works like a mixture of Reddit and Blogger, with incentivization in the form of Steem. TheDarkOverlord is the hacker group who says they have damning evidence and 9/11 papers. Yesterday, Steemit banned TheDarkOverlord. The hacker group uses Steem to publish his communiques and demands. They were previously banned from Twitter.
Steem should not be confused with Steemit, which is the first and most-used platform built on Steem. Several other platforms have been built on the Steem blockchain. D.tube is one that mirrors the functionality of YouTube. Busy.org, on the other hand, acts as a total alternative to Steemit.com.
Steemit.com maintains a list of users banned for Terms of Service violations and for GDPR purposes. It’s important to note that these users cannot be banned from the blockchain itself. Using their WIF, they can access their Steem wallet in a variety of ways. And using the Steem blockchain, other services can display banned content. It is unclear why exactly the 9/11 papers hackers were banned, but there are multiple possibilities.