The solution isn't easily found even when reading the document referred to when starting Wireshark as root ("/usr/share/doc/wireshark-common/README.Debian").
sudo dpkg-reconfigure wireshark-common
Answer 'yes' to "Should non-superusers be able to capture packets?"
Then add the user account(s) to the now-created "wireshark" group (replace $USER with the user account name):
sudo adduser $USER wireshark
Log-out completely and log-in again for the new group membership to be recognised.
This issue is still biting on Precise LTS.
The solution isn't easily found even when reading the document referred to when starting Wireshark as root ("/usr/ share/doc/ wireshark- common/ README. Debian" ).
sudo dpkg-reconfigure wireshark-common
Answer 'yes' to "Should non-superusers be able to capture packets?"
Then add the user account(s) to the now-created "wireshark" group (replace $USER with the user account name):
sudo adduser $USER wireshark
Log-out completely and log-in again for the new group membership to be recognised.
Start "Wireshark" without using gksudo/gksu/sudo.