The animal rights group People for the Ethical Treatment of Animals (PETA) has called on singer Britney Spears to call off her plans to appear during Thursday night's MTV Awards with live cheetahs. In an open letter to Spears, parts of which were published in today's (Wednesday) New York Post, PETA's Dan Mathews wrote: "We hope you'll open your heart to the plight of captive 'wild' animals caged and forced to tolerate bright lights, crowds, and frightening levels of noise. ... Cheetahs used in show business are often trained through intimidation and with such devices as electric shock prods and sticks. ... Whippings, beatings, and starvation are common methods used to break the spirit of free-roaming, independent animals." A spokesperson for Spears declined to discuss the PETA letter.