A few years ago When I was in Poland, in some stores I saw a notice: (Touched goods are considered sold).
Indeed, there used to be such notices quite a long time ago, but these were only about selling bread. Some customers were even paraphrasing it into "Towar macany uważa się za sprzedany" or "Towar macany należy do macającego" which sounded funny. But I haven't seen this notice for ages now.
There used to be quite a few funny notices in shops during communist times. An intelligent film "paraphrase" of that can be seen in one of Stanisław Bareja films where customers who were too annoying to shopkeepers in shops which had almost nothing to sell were caught by the staff and then taken portrait photographs of which later were zoomed in and displayed at the door of the shop under the big heading "Tych klientów nie obsługujemy
" (Those customers will be refused to trade with here).