Great tool. need do some changes as below said by Trenton VanderWert. You mayb also see this info from /usr/share/doc/wireshark-common/README.Debian
sudo dpkg-reconfigure wireshark-common
press the right arrow and enter for yes
sudo chmod +x /usr/bin/dumpcap
you should now be able to run it without root
摘自:Ubuntu软件中心