"It's a nonsensical idea," he told an audience at the London Film Festival, likening the notion to helping oneself to "free shirts" in a clothing store.
Video-sharing sites like YouTube, he continued, were doing a "massive disservice" to the film industry.
He went on to praise France for passing the world's "toughest" anti-piracy law.
In 2009, France adopted a so-called "three-strikes law" that means persistent pirates can be thrown offline. The legislation, Weinstein claimed, had "disincentivised" people to "steal" content and had resulted in a "robust" local industry.