Minnesota Teen Pleads Guilty in Web Worm Hack Attack By GENE JOHNSON    SEATTLE (AP) -- A Minnesota high school senior pleaded guilty Wednesday in federal court to unleashing a variant of the "Blaster" Internet worm, which crippled more than a million computers last summer.    Jeffrey Lee Parson, 19, of Hopkins, Minn., is likely to face 18 months to three years behind bars after pleading guilty to one count of intentionally causing or attempting to cause damage to a protected computer...