Could this be a possible design fault?

When an admin of a group oganises an activity for others to attend, all of the group members can be informed ...good idea.  

However, when/if this activity is then cancelled (due to the weather or other reason), could something be changed so that only the people concerned with the activity (those who had signed up) be informed of it's cancellation, and not the whole activity group (others who have not signed up)?

As it is, everyone is informed and it annoys some, especially if the activity doesn't even interest them at all...  Just an idea.

Cheers!  :o)  JT.