A US mother of five has been slammed with a $22,500 fine for file-sharing by the courts, which rejected her defence that she had been using such networks to sample music to buy later.

29-year old Cecilia Gonzalez was fighting against the RIAA, which demanded she pay $3,500 for an out-of-court settlement.

She took the case to court, but the judge found against her and ordered her to pay $750 for each of 30 songs she was accused of distributing online. The Gonzalez case was one of the first begun by the RIAA.

The judge declared that a track downloaded from the Internet is a substitute for a purchased track.