1
general::
Also, tear into. Attack or criticize vehemently, as in She ripped into her opponent's voting record. These expressions allude to the literal senses of the verbs rip and tear, that is, "cut" or "slash."
American Heritage Idioms
2
general::
Phrase(s): rip into someone or something
1. Lit. to attack someone or something by ripping. • The raccoons ripped into the trash bags, scattering papers and stuff all over the street. • The horrid murderer ripped into the helpless victim. 2. Fig. to criticize or censure someone or something severely. • The drama critic ripped into Larry. • The critics really ripped into Larry’s poor performance.
McGrawhill's American Idioms And Phrasal Verbs