First I've heard of these. I must be out of the loop.
Was the first truly warm sunny day here yesterday and I saw lots of teens wearing them. At one time I would have said such things (basically hotpants) were slightly indecent and never wore them myself when young - but these girls looked fabulous, mostly paired with trainers, tshirts or hoodie tops (yes, in that weather!) and they looked more put together, sporty and practical than the disco-hotbabe-hotpants of my youth.
I actually had a moment's regret that I wouldn't be trying it out 
Looked online later and and noticed they're referred to as Booty shorts. Will probably be purchasing some high waist denim ones, a wee bit longer in the leg, nothing too cruise-like though.
I have also noticed the Deee-Lite style coming back in the shops, lots of pastel colours with whopping huge daisies on.