LeAnn Rimes -- Prepping for Lawsuit against Alleged Phone Tapping Bullies

LeAnn Rimes believes she's the victim in an scurrilous phone recording conspiracy ... and now her lawyer tells TMZ she's gearing up to sue the scumbags behind the illegal activity.

TMZ just spoke with LeAnn's high-profile attorney, Larry Stein, who tells us the singer has been victimized by a gang of cyber-bullies who have been terrorizing her on Twitter ever since she hooked up with Eddie Cibrian.

Stein says LeAnn recently spoke to one of the bullies on the phone ... but unbeknownst to her, the bully recorded the convo ... and spread bits and pieces of the recording around the Internet.

Recording a phone call without consent from both parties is illegal in California .. and Stein tells us LeAnn will "Take all of the appropriate steps to address the harm that [she] has suffered as a result of this criminal conduct." Translation -- she's going to cops and wants them prosecuted.