"The studios had been reluctant to join the ongoing legal battle between sanitizers and directors, largely for fear of seeming to oppose advocates of film decency. "We were dragged in kicking and screaming," one executive said."[...]
"Some operators, including CleanFlicks, rent videos from which offending scenes have been edited. Others sell software that lets consumers edit a DVD copy to their own specifications. CleanFlicks has argued that it doesn't violate copyright laws because it buys a new copy every time it edits a film."
But they're still not reselling the original copy that they bought. They're simply making a dub of the edited copy they made, then presumably tossing the one they bought.