Check with your hand phone; make sure that your hand phone can still make a call before you enter a restroom.
And after entering into that particular toilet, if your phone cannot make a call out (this is due to the interference of fiber optic during implementation), it means that there is a HIDDEN CAMERA inside, and so be very cautious ladies!!
PLEASE ALSO PASS THIS TO YOUR MOTHER, SISTER, AND GIRL FRIENDS FOR ALL MALE!!!!