Interesting, how do you tell your kids that the backups you are making illegally are O.K.? I don't think you can rely on technology for what you should be doing. Watch the movie ahead of time. Edit out the offending sections using DvdShrink. It is a lot easier, in the sense that then you can be absolutely sure the content is not in there, as opposed to taking the easy way out, if this is really an issue.