The New hampshire statute:
CHAPTER 472
BOUNDARY LINES
Section 472:6
<B> 472:6 Removing or Altering Boundary Markers. 捧/B>
I. Any person who purposely commits or causes to be committed any of the following acts with regard to a boundary marker knowing it to be a boundary marker shall be guilty of a misdemeanor: defacement, alteration of location, or removal of a stone wall or monument, or a mark on a tree, made for the purpose of designating a point, course or line in the boundary of a tract of land or in the dividing line between towns.
II. The provisions of paragraph I shall not apply when a boundary marker is moved pursuant to:
(a) Mutual agreement between all landowners whose property lines are affected by the moving of the boundary, or
(b) Authorization by government officials in order to more accurately place the boundary, or
(c) A finally adjudicated court order or decree, or
(d) A law that requires or allows the movement or alteration.
Source. 1983, 21:2, eff. June 11, 1983.
Was once held up for several weeks on a construction project when an abuttor, also a planning board member in abstencia, non-specifically disagreed with our survey. Ultimately we found a second survey mark, a drilled hole in a buried rock, that created a strip of land that tapered from 18" to nothing over 300'. Neither party claimed ownership. He knew of both marks and just declared the disagreement to interrupt our work as he had previously tried to buy the property for a lowball sum.
If it's just a surface problem, and not installed specific to elevation, one could just drive it below grade enough to clear the plow. A surveyor in my area uses a 2 piece rebar pin connected with a piece of pipe welded to the lower half. If someone pulls the top out of the ground the other piece remains 18' below grade & is easily relocated. MikeD74T