Stars under attack! Girly-girl Nicole Richie‘s sweet, petite and just five feet tall, y’all — but The Simple Life star shocked shoppers at a BevHills drugstore when she suddenly, savagely whipped UP on the butt of a chunky-momma wallet-snatcher!

Nicole, who had her purse perched on the front of her shopping cart, was cruising for personal hygiene items, turned to take something off a shelf and… out of the corner of her eye, she spotted a sneak thief swooping in for a sting! “HEY!…”

Nicole shrieked as Light-Fingered Lulu brazenly lifted the star’s wallet out of the purse. ” … what the HELL are you doing?” As shoppers gasped, Richie girl-handled the much-bigger 5’5″, 145-pound woman, slamming her up against the toothpaste shelf and pinning her — then howling bloody murder as security guards came running. “Good job, ma’am… we’re calling the police,” they told Nicole. Then the frightened woman started weeping, apologizing repeatedly and babbling about how she’d fallen on hard times. Incredibly, soft-hearted Nicole told guards to let her go — refusing to press criminal charges!