For a Vietnamese émigré accused of robbing only Chinese people, familiarity breeds contempt. But then Hanoi-born Ha Vasko, 68 -- a slight woman whose toothpick frame vanishes into her brown drab Rikers Island jail uniform -- is not your typical pickpocket. The serial thief usually flies Delta from Melbourne, Fla., where she lives richly with her golfing American husband in a $400,000 waterfront home, to New York City's cacophonous Chinatown with only one thing on her mind.