Threads can be very useful tool if they have the right permission.
Current situation
Any thread created inside workspace is visible for observers (and members). These threads display in the sidebar. If user doesn’t have access to the entity thread belongs to then user can see only thread and cannot see content of the thread or send message. They can see comment field and send button but sending won’t work.
Solution
Display only threads of the entities that users have permission to see. This will clean threads for users because if you have 50 threads then user can see all 50 even if they have access only to one entity and they will need to find the only one that they have access to.