This is a comment I made before

1. Nothing can be removed from the blockchain. Ever. "Regulation" isn't going to change this.

2. Any app can choose any policy it likes for what it presents to the user. This means evil stuff can be blocked.

3. The user can choose what app they want to use. They can choose to use an app that blocks porn, or an app that blocks political stuff they don't like, or an app that only blocks child porn, snuff porn and rape. Or an app that blocks nothing.

4. Steemit.com works by simply blocking anything with negative vote counts. This means anything voted down to oblivion is invisible automatically. You can also report genuinely illegal content to Steemit and they will ensure that their web app does not show it.

In the case of copyright, it will be hard to enforce. They can penalize people who post copyrighted material, but actually removing it from the blockchain will not be viable.