Bristol Palin, Keith Olbermann Trade Barbs

Bristol Palin is striking back against MSNBC host Keith Olbermann for dubbing her "worst person in the world."

Olbermann gave her the title on his show earlier this week, casting her as a hypocrite for appearing in a public service announcement promoting abstinence and safe sex. Palin was an unmarried teenager when she had her son, Tripp.

He likened her being an abstinence spokeswoman to saying former President George W. Bush "kept us safe, 'cept for that 9-11 thing, which doesn't count."

The 20-year-old "Dancing With the Stars" diva and daughter of former Alaska Gov. Sarah Palin defended herself on Facebook Thursday. She said calling her a hypocrite is an "old canard." And she said that what Olbermann lacks in originality he makes up for with "insincere incredulity."

She said she apologized to him for not being "absolutely faultless like he undoubtedly must be."