I had some joyjolt double walled expresso cups and the slightest jolt would make them shatter into multiple sharp edged shards. Never owned anything as breakable as those cups.
Joycect I am surprised by your comment as I own a set of JoyJolt double wall glasses for over a year already and they are by far the best glasses I have! I use my set daily and have not had any issues with it! Perhaps yours was a defective set .. try reaching out to the manufacturer they may be able to assist you!
benpreezHe's on drugs--I own these, and several others just like them. They are not overly fragile in everyday use--and I use mine everyday. On the other hand, drop one on the floor and they'll break; just like all the other glassware in one's cupboard.