I've seen a number of people in my extended social circles do varying combinations of A and B, but still eventually losing because of a failure to do C, because they don't want to be confrontational or whatever.
(I am specifying "in the US" because I'm fairly sure this is related to common law. Countries operating under other traditions may not see this effect. However in common law, there's a certain element of having to be able to "defend" your property in order for it to be yours.)
The 'neutral strip' that they auctioned off, was actually the very tippy end of the road (which they can do, unless it hinders someones driveway access), and we lost access to our second driveway, which is entirely illegal except there's a whole bunch of legal nonsense you have to submit to keep a driveway valid after it becomes blocked for a certain period of time, otherwise the driveway is automatically considered cancelled (in this case, his pergola blocked it for long enough that you need a new driveway permit if you can believe it). A new driveway permit can not be approved if the driveway can not be accessed, and so the fun begins. To make the driveway valid, and hence the sale of the land under the pergola illegal, they made it seem like we needed to forfeit the strip to general access...
I'm not even being sarcastic when I say that surveying property borders, roads and driveways seems like a perfect application for an immutable and easily auditable blockchain based on lat/lon.
(This is getting complicated and challenged due to the fact suburbs are popping up nearly everywhere and totally useless land may now be worth money.)
In the case above simply demolish whatever the guy built. He tries to sue in civil court and fails because he had no right to build there.
Despite not having lived on the farm for 25 year my mom and dad are often brought out to help settle dispute regarding property lines.
Technically everything is mapped out and moving a post or plowing a wrong part of the field doesn’t change ownership, but some of the maps are old and reference point are no longer where they once where.
Here in Germany, he would be issued a demolition order by the court that, in case of non-compliance, will be enforced even with armed police if deemed necessary. On top of that the affected party can sue him for damages.
https://www.vg.no/nyheter/innenriks/i/GkGJm/nabotvist-paa-ne...
The guy who did this also rubbished 70 year old stone fence - erected a generation before he was born, and ended up in jail after a number of court cases. Talk about pissing your life away because of misplaced anger.
https://www.aftenposten.no/norge/i/4deprG/huskapper-i-asker-...