So, pretty sure I may have just started a war.....time will tell.
I was out in the side yard area behind the garage/workshop starting to scope out where I am thinking of putting the coop because there is a bit of work I need to do to clean it up and level it out......there were several trees taken out back there right before we moved in and it wasn't very well cleaned up. Anyway, came across a lovely pile of dog crap -- not one "pile", a PILE of crap -- seems the people in the apartment behind that part of the yard have been cleaning their patio area (where they leave there dog) by scooping up the crap and throwing it through the chain link fence (the apartment complex has the entire length fenced with chain link, the privacy fencing our landlords put in only extends to from the corner of the garage closest to the house and then across the back yard immediately behind the house so that we have a small area of closed yard for the dog) right into our yard...........

It has clearly been going on for a fair bit from the sheer amount of crap that is piled up back there....not to mention assorted other crap that has been tossed over.
So, whipped out my phone, took several photos for documentation and marched my happy self on over to the rental office and informed the manager what I had found. She was very responsive, walked back over to the house with me right then, took several photos for her own records and will be sending the tenant a notice today about the situation. She said if it does not stop or, as I worry it might, escalates in retaliation I need only let her know as she is NOT amused by this and is fully prepared to escalate things with regards to the person being able to continue to live there if they don't knock it off.....just not looking forward to the possible unpleasantness in the meantime if it does come to that.
Seriously, who does that????? It's just lazy, nasty and rude..........