A US judge has moved to overturn the conviction of a Missouri woman accused of bullying a teenager who later committed suicide.

District Judge George Wu has ruled that Lori Drew was not guilty of violating the Computer Fraud and Abuse Act, overturning an earlier jury decision that convicted Drew on three misdemeanour counts of unauthorised access to a computer.

The 50 year-old housewife was accused of bullying 13 year-old Megan Meier, a former friend of Drew's daughter, through social networking site MySpace.

According to prosecutors, Drew created an account for a fictional teenaged boy named 'Josh'. The fake account was then used to flirt with Meier. After conducting a brief online relationship with the girl, 'Josh' then ended the relationship and began to taunt Meier, who later took her own life.

Shortly after Meier's suicide, Drew was brought up on felony and misdemeanour charges of illegally accessing a computer. A jury in Los Angeles acquitted Drew of the felony counts, but returned a guilty verdict on the three misdemeanour charges.

The case raised a heated debate over how cyber bullying cases on the internet should be handled, in terms of the charges that can be filed and the jurisdiction local authorities can hold over online activites.

Judge Wu appeared to echo those concerns in his decision. According to the Los Angeles Times, Wu stated in his ruling that, by bringing criminal charges against Drew, prosecutors were equating any violation of a site's terms and conditions with a crime.

"Is a misdemeanor committed by the conduct which is done every single day by millions and millions of people?" Wu was quoted as saying.

"If these people do read [the terms of service] and still say they're 40 when they are 45, is that a misdemeanor?"