This cyberbully has been cut down to size.

An online retailer who threatened to rape female customers for complaining about his shoddy merchandise pleaded guilty yesterday to federal charges that could send him away for 6½ years.

Vitaly Borker, 35, said he sold about 100,000 pairs of glasses through his DecorMyEyes.com site, claiming “most” complaints “were handled professionally.”

“However, I wrote e-mails to a few of the people who complained and threatened them by saying I knew where they lived,” he admitted in Manhattan federal court.

Google revised its software after Borker publicly bragged that online complaints helped pushed his site up in search-engine results.