The Cross of Confusion

Had trouble with my laptop yesterday which necessitated a trip to a computer repair shop. So here's the blip I couldn't post.

I came across this mark cut into the local sandstone. I believe its called the Cross of Confusion or the Cross of Questioning and is supposedly a Roman symbol which questioned the validity of Christianity. Quite why the Romans needed such a symbol, how and where they would display it seem to be unknown. It is also said to have been adopted as a satanic symbol.