I have a mainland parcel, I've landscaped it and that landscaping includes some trees that I really love.  Recently I got a new neighbour, this neighbour started returning one of the trees.  At first I thought it was somehow impacting his Li for his parcel, so I pulled it back.  Logged in the next day and found it returned again, no message from the person.  So, thinking there was an SL glitch with LI, I linked the tree to another prim that was far in on my parcel to assure there was no LI issue