Today the sign poster's identity was revealed. Apparently, he was taking out the trash a few nights ago, and an improperly sealed bottle of piss leaked on his leg. He was so upset, that not only did he post his signs, but went door to door threatening to kill anyone who he caught pissing in bottles. Further, he routinely sifts through the trash looking for piss bottles with clues, so that he can track down the vile person pissing in bottles:
(psst... It's everybody.)
Today he found a bottle of piss in a plastic bag, inside that bag was also a receipt. He brought it to his First Sergeant. Finally, a lead; the bottle pisser SHOPS! Not only does he shop, but he shops at the PX!
(psst... So does everybody.)
I will keep you posted to any more breaking news from the case.