How do I delete a video on Vine?
To delete a video on your Vine app, tap the three dots at the bottom of the video you want to remove. Select "Delete post" and the video will be deleted from your account. It may take a few minutes for the video to disappear from your followers timelines.
dfrgeege replied on Permalink
To permanently delete photo,video and other files on iPhone,you can use a iPhone data eraser,there are some iPhone data eraser software in the market, but few can be completely and permanently delete the data on iPhone, even if data has been cleared, some professional iPhone data recovery software can recover them later.
Please read this use guide about how to Permanently Erase iPhone Data Before Selling your iPhone.So no one can get you personal information and data from iPhone,after you sell, donate or give it away.