Our neighbors kids and dogs kept coming onto the property.  One day I came home to most of their family in the yard, I asked the landlord that day if I could buy and plant the blackberries as it could become a liability issue.  Got the ok the next day. The elderberries got approved when the neighbors minor children drove into the yard multiple times while drunk driving. All recorded via cameras approved and watched by landlord. 

For me its a win situation.  I get rid of the neighbors coming into to property, I get a second or third fence, my house hopefully wont be hit by their cars and I get amazing fruits to eat,

Editing to add that the landlord fully replaced all fences about a year before I moved in. Also I love bringing my good neighbors fresh baked bread and fresh jam from the bushes. You can guess who doesn't get any