Stress levels on Upper East Side are rising, the NYTimes reported on Friday. Impulse buying is down, as is luxury shopping. And while yoga is doing quite fine, thank you, bad behavior in classes is on the rise. Put that crackberry down, Suzie! The NYTimes reports from Pure Yoga, the Asian-inspired yoga boutique owned by Equinox Fitness: "Ms. Demus has been battling a growing number of people trying to check their BlackBerrys and take cellphone calls in the middle of yoga sessions. Her instructors “gently” tell them to switch them off and perhaps take a break from their worries. “It’s great for them to realize that the world will continue spinning,” Ms. Demus said, “if they let go for an hour.”Image: Suzanne DeChillo/The New York Times Or maybe it's the space-ship lighting at Pure Yoga making them frantic?