From the jira Description:
Griefers are still able to spam you with dialogs, such as dialogs, web site popups, and avatar animation requests even after you mute the owner of the object. Muting does not stop these at all. This is an ideal path for griefers to attack and they have been doing so for as long as I've been on Second Life. I believe that muting the object or it's owner should stop dialogs of all types from appearing from the object.

Note:
The changes to message_template.msg are not mine; that file was pushed from the server source into viewer-development.  I have no control over what goes into that file or how it is formatted, etc.

See lengthy Test Plan in the jira.