In my Italian textbook I encountered these two sentences: "Ti piacciono i romanzi gialli?" and "Ti piaccioni i film gialli?" I thought "piaccioni" was an error, but I am finding the "piaccioni" version when searching Google.
100% sure it is a spelling error.
There is another word "Piacione", for definition check here that at plural it becomes "piacioni" and if mispelled it becomes "piaccioni"...