Lots of people seem to be posting the 8 Ball emoji on Facebook at the moment but not really saying why. It seems to try and raise awareness for Prostate Cancer.

The first refence for the 8ball having anything to do with Prostate Cancer is on here: Petey's raising awareness for Prostate Cancer!: Behind the 8 ball

I wonder if it's in reference to: "Behind the eight ball" as an idiomatic expression meaning "in a difficult situation" from wiki.