I gotcha. But actually at this point I'm a little more concerned that
neighbor #2 would try and force me to move the fence back over to my
property. I guess I'm clear on the adverse possession/prescriptive
easement laws in my area, but I have no idea regarding ownerships of
fences and responsibilities to move fences that were built by others,
or perhaps more importantly, what is customary.

Basically, I'm a little worried that I may have to pay some money to
move a fence back over to my side of the property line when I'm not the
one who put up the fence in the first place. In my opinion, if
neighbor #2 wants the fence moved, he should pay to have it moved
himself - I have no objection to that. But I don't feel I should pay
to move a fence that (1) I didn't build (2) the neighbor saw being
built and never objected to. But I'm curious if my position is
unreasonable. I'd kind of like to know before I talk further with
neighbor #2, in case he asks me to move the fence.