Not a foster/adopt update

I'm livid.  I had a relatively decent day.  Then I got home to a letter from the city - specifically animal control - telling me someone had complained that my dog had "been allowed to bark excessively."  Excuse me?!  He spends all day in the house!  When he's in the house, he only barks if someone comes to the door or there's some similar noise of someone being in our space.
We've been here almost two years, so I don't think it is the elderly man next door as surely he'd have complained by now.  So it has to be someone in the house next door which is a home for young women of every shape, size, color, and type of relationship with their children.  Right now, the house is full of young women either with children there full-time or part-time.  There hadn't been kids there until recently.
I can only imagine that is the change that prompted a complaint.  Maybe Samson woke someone up at 6:30 in the morning.  Or someone came home and he startled her kid.  I don't know.  But no one was brave or honest enough to come to me about anything.
And he's a dog.  Dogs bark.  Squirrels are his mortal enemy, so he barks at them.  Isn't that a natural thing for dogs to do?  He's also protective.  When someone's walking through the ally behind the house and he's outside, he lets me know there's someone around and lets them know he's standing guard.
Mom seems to think it's an isolated incident and we just need to be careful for a while.  Greg suggests I kill the squirrels.  Not sure either has it quite right, but I lean toward killing the squirrels.  Actually, I am feeling very motivated to build a 10-foot-high privacy fence so they can't see him and he can't see them.  And I'll put in some kind of water feature...or maybe wire some speakers and play some kind of white noise so they can't hear each other either.
And maybe the next free moment I have I'll find out what city law says about smoking outdoors and how far you have to be from your neighbor's property when you do.  Then I'll measure and send the city after them.  Or maybe I will politely ask them to smoke at the back of their house instead of in the driveway where the smoke can waft over into my doors and windows...the cowards.