Ideas vote notification displays profile of last user who voted on the idea .
This would be a privacy concern if the user down votes the idea .
This is working as designed as part of the larger notification infrastructure, which shows the avatar of the notification actor (the person who made the action) in certain places in the UI of notifications.
If you prefer not to show notifications on idea votes, you can disable the 'Idea Vote Notifications' plugin via Administration. There are also settings for that plugin to specify a time span within which all votes will be grouped as a single notification, which would improve anonymity somewhat, though there is always the chance that a single down vote would occur within the specified time span.
though there is always the chance that a single down vote would occur within the specified time span.
Yes that's correct . This forced us to disable the idea votes notification since we do not want to modify the default widget to hide the user .