Thanks for your answers everyone. This is the what I get when I do "who". I do indeed have three terminal tabs. I had a browser open with four tabs. I'm not using multiple desktops, to the best of my knowledge! Why so many tty? I have only one ethernet connection to the gateway supplied by ISP. Wifi turned off on my laptop. I'm not sure if I can legally access the router and change settings, if that is possible. It is a dual gateway, one for open wifi ISP's users to access and one for my "network" of one laptop using ADSL. The ADSL phone and ethernet connection runs through two power lines from loungeroom to study. Telstra Air plan if that helps at all. Its a Netgear gateway.
mint@mint /var/log $ sudo su
mint log # who
mint tty3 2015-12-02 20:42
mint tty2 2015-12-02 20:42
mint tty6 2015-12-02 20:42
mint tty5 2015-12-02 20:42
mint tty4 2015-12-02 20:42
mint tty1 2015-12-02 20:43
mint tty8 2015-12-02 20:45 (:0)
mint pts/0 2015-12-02 20:59 (:0)
mint pts/2 2015-12-02 21:58 (:0)
mint pts/4 2015-12-02 22:32 (:0)
Last edited by mazinoz; 12-02-2015 at 08:33 PM.