Member 'admin' has been registered for 11 months and signs off posts as Zia (and Jp and Tilly and Nippa and Steven and many other names) and has the improbably high post count of 51,595.
Suprised you've only just noticed him/her given that - despite being a member since 2013 - those posts seem to go back as far as 2007 ...
http://www.whathifi.com/forum/mp3mp4/samsung-k3
So I am guessing that this is a fault in the system. On one old post someone has quoted 'admin' but the quote shows the member's user name as 'Tilly Masterson'.
Strangely, user 'Anonymous' (not clickable and no details of when joined or post-count etc.) frequently appears in threads posted by 'admin' (also as far back as 2007).
Looks very much like something weird happened after the website change and that 'admin' is/has been many users (even concurrently) but always with the same 2013 join date and other details (last visited , post count).
[Update] When 'admin' posts a thread he/she is user 'admin'. When 'admin' makes subsequent posts in reply to other posters (in the same thread) the replies come out under the 'Anonymous' user name like in this example ...
http://www.whathifi.com/forum/hi-fi/cd-player-cyrus-setup
This is not the only example. It happens in all of the threads where 'admin' has both posted and made replies. (All those I have checked anyway.)
This even happens in recent posts ...
http://www.whathifi.com/forum/network-players/sonos-amp-qa-concept-20-speakers
I am going to check if this happens on the iPad now. I can't believe 'admin' (and 'Anonymous') are not seeing this themselves, so maybe it's platform dependent or only visible to certain users (like PP and me).
I will also try without being logged in (after deleting all cache, cookies, history and temp files etc.)
[Update 2] Ok, without being logged in, this what I see from a recent post ...
http://www.whathifi.com/forum/network-players/sonos-amp-qa-concept-20-speakers
Thanks