I know that this matter is not strictly "interPERSONAL", but that's the problem -- I know there's a cat but I don't know who the owner is.
All I know is, the home owner association I live under is the stereotypical one run by spiteful old people. We do have a mailing list, but posting a complaint/plea there would more likely cause them glee than give me a straight answer.
We are 37 households, and only we and 2 others have (small) kids -- the rest are pensioners. We are talking with only two other households; there is not a lot of communal spirit here -- the first HOA meeting I attended, about a week after we moved in, made it clear to me (in ways I shall not go into here) just how hostile, ludicrously infantile, and petty these people are (even towards each other, not just "newcomers"). Later, I requested that the run-down communal play area receive a bit of maintenance, only to be shot down rather rudely. I am decidedly not in good standing in their minds, and that is why I cannot think they would be very inclined to help me avoid their cat's poop in my garden.
I don't mind cats (or dogs, birds, etc.) but I very specifically don't want a pet in my household. Yet I have a problem that I'm unsure of how to deal with in a reasonable way. This is all in Denmark, so US laws and customs may not apply.
This year, a cat has been pooping in our garden, and ripping out grass or whatever else was around the scene of the crime, to cover it up. I obviously don't want this to continue (I would like my garden un-ripped, and my two small daughters would prefer it un-pooped-in also). It also has been leaving little puke pies around our cars in the drive way, which are quite disgusting, too.
But how do I stop the cat? I have tried planting "scaredy cat" plants, whose smell were supposed to discourage cats from coming near, but they don't work. I have also tried putting down metal webbing in the flower beds (because I heard that they don't like to step on such things and/or can't dig in it), and while that worked I can't extend that practice across my entire lawn.
Local law says that it's the responsibility of the pet owner to make sure that one's pet does not annoy others. This means I should go talk to the owner of said cat and ask them to keep the cat out of my garden. To which I would object: (a) I am convinced that no cat owner would agree to confining their cat because it roams in places that other people don't want it to; and (b) I don't even know whose cat this is! I have caught a glimpse of one cat, and followed it to the garden of a neighbour who has a cat door in their front door -- I am aware that this says absolutely zero about whether it's their cat or not. I have obviously not been able to read the chip or tattooed number in the cat's ear either.
How can I ask my neighbors - so that I will have an honest answer - who is the owner of this trespassing cat?