On a scratch profile, this button will appear next to their username. If u press it, you wont see messages from them and they'll be hidden in comments and notifications. It'd be perfect for bullies, or rude people in the Scratch community. Also you won't see their username ANYWHERE except for where you can unblock users.

How to Unblock users (if this gets added in)
To unblock users, you will need to go to maybe “My stuff” or settings, then you will drop-down into Users Blocked. Then, you can select one of the users you have blocked, and if they've became friendly, or you just need to unblock them for whatever reason, click “Unblock”.

Idk if this will get added in tbh.

when flag clicked
block (TheBully6000) 
set [recent blocked user] to [TheBully600]
add [TheBully6000] to [blocked users list]

dear sir it’s rejected

The Official List of Rejected Suggestions wrote:

8.6 Blocking or ignoring Scratchers

This suggestion refers to an optional system that makes it so that you do not have to see comments that a particular user posts. This feature existed in Scratch 1.4, but the Scratch Team found that it buried any problems rather than solving them. Even if you block a user, that does not stop them from harassing other Scratchers. If someone is being disrespectful, be sure to report that user with the Report button, or use the Contact Us link if the situation requires more explanation.

‎

However, a system to block users while simultaneously reporting them is NOT rejected. You can discuss them on this topic.

View source

oh-