Early yesterday morning I found a wee Ikea step thing on my roof terrace. It had been dropped by my upstairs neighbours. I went up and left it outside their door as it was too early to wake them.
Yesterday afternoon, when I got home from my bike ride, a local ne'er do well had taken a crap on my flat doorstep.
Yesterday evening I got home from meeting friends in the park and my step-dropping neighbours from this morning had left me an unknowingly sardonic thank you:

Someone had taken a sh1t on your doorstep?
You need to move mate 🙁
Someone had taken a sh1t on your doorstep?
You need to move mate 🙁
Exactly my thought
But then again, there is the upside of neighbours leaving brownies on the doorstep? OP took some lumps for sure, showing that you can’t always have your cake and eat it.
Yesterday afternoon, when I got home from my bike ride, a local ne’er do well had taken a crap on my flat doorstep.
Not the ‘crack of dawn’ deposit type then? More of a lazy-afternoon log?
OP were there any possible identifying features? We need to get (No Shit) Sherlock on the case.
Edinburgh has a bit of an issue with shitters shitting in the close.
Put a note through their letterbox, ‘No problem with the stool but please don’t drop any logs’
I'm guessing your definition of "sardonic" comes from a different dictionary than the one I use. People leaving brownies on the doorstep is amusing though.
Did you disinfect the step? If not then you probably have parasitic worms by now.
Hols, I imagine YGH meant sardonic in the sense of life in general mocking him rather than any particular actor in the story.
I'm more concerned about the neighbour using xmas note paper to write thank you in June.