Their neighbor put up a fence, but it's actually on their property. When asked to take it down, they claimed "squatters' rights." ...
If installing a fence directly on the property line, both neighbors usually contribute to the cost as the fence is shared. But if the neighbor refuses to pay, the homeowner can sue for the neighbor's ...
If you ever consider planting trees, putting up a fence, or anything else on your property, do yourself a huge favor and have a survey done to make sure you know exactly where the property line is.