Can I disable share in graphical view, watchlist and report modules so that users cannot see other's login id ?
Disable share in Mango
It would be really easy to remove the share button from the User Interface, you should be able to do that in the .jsp file but this would remove it for admins as well. You could always use the Import / Export to update the shares. We are planning on making some improvements to the User Management system in Mango and could probably include this as an option.
Thanks for the idea,