It’s the ultimate irony- in order to properly use this No Sign and tell people not to use their cell phones, you actually have to use your cell phone. Well I guess technically since your phone is in the sign, you won’t be using it. You can also put anything else you don’t want people to do in the sign’s strap too.
The “no” part of the sign is made from rubber to stretch around whatever you put in there. I guess since your phone is in there, the sign really says “no cell phones- except for mine”. Too bad they don’t sell a smaller version of the sign so you can slip it in the bigger one and just say no to no signs.