The thing about steem. It is a blockchain not owned by a centralized agency. It is also based on open source code. So it would difficult and near impossible to insure it is completely shut down. That is one of the reasons people want decentralized things.

They could target the websites that allow you to view the blockchain, but those too are open source (at least steemit is) and you could spin up another website to access the blockchain almost anywhere.

So this would be one of the more difficult things in existence for them to just SHUT DOWN. Just like they can't shut down bitcoin.

They could make it difficult to use it, but to completely eliminate it would be difficult.

This is assuming it is actually setup like I think it is. :)