Well I can assure you this person is able to know what sim I am in at any time, I have not to my knowledge accepted any items from this person that a tracker could be concealed in, normally an item you wear I believe.
No one on my friends list has mapping rights so if this person has an alt I am friendly with then they cannot track me that way.
I wear no huds only an AO.
I could pick a sim at random that ive never been to and this person will know that I am in that sim.
Maybe someone has now devised a tool to track without having to give an item with a tracking device in it ?
I am sure someone in this forum knows how this person is tracking me so I guess I just wait for that reply