Could you use facial recognition software on backsides?
You could try, but everyone you scanned would be identified as Popeye the Sailor.
And then use the results to tell your fortune. This could revolutionize Rumpology as we know it!
Where is this place that people bare their butt and cover their face?
No, seriously, I want to go there.
You may be interested in the movie Eyes Wide Shut. You’re welcome.
I’m almost loathe to ask, but do you have a reason for asking this?
I like to think that I can recognize Sophie Sweet’s ass in a sea of asses, through the fog, at 100 yards.
Wha? No mention of J-Lo yet?
I get recognized from the back a lot. Even when I’m wearing a hat.
I don’t know about butts, but I once recognized a teacher from my middle school by his man-boobs. I was sitting down and he walked past, and I thought, “Hey, that looks like Mr. Wardrum.” And it was.
That’s because nobody else wears a hat on their ass 
I bet that goat guy sure is easy to recognize.
I knew someone in high school who could identify every member of the football team from their butts. The woman obviously had a talent.
Baby got back!!