Most media companies or producer argue that you are not able to remove M4V video DRM for any reason, as it is illegal. I just would like to state in this article that, if the software crake DRM protections from M4V video, it's not allowed; if the M4V Converter tool take another way to remove DRM, such as record M4V movie or other legal method, it's legal way to free iTunes videos. So, advice for you: choose the legal software to remove DRM from iTunes M4V files.
So far as I know the legal software to Remove DRM from iTunes videos
Three steps to remove iTunes M4V DRM.
1. Install and launch M4V Converter for Mac
2. Import M4V movie you purchased or rental from iTunes
3. Click "Convert" button to free M4V DRM protected.
As I said above, you should choose the legal software to free your purchased movie from iTunes, if there is any other software can remove DRM as legal as M4V Converter for Mac as mentioned, welcome to share with me or whoever care about this topic.