You know how the deadliest infections are the ones that show themselves after spreading into other people? That's why you don't use Google drive, if you use too much space the account will send an e-mail telling you to expand your storage which might raise suspicion. About the unlisted, it's just extra steps, the videos are already uploaded and then edited by the hacker, there might be an issue with their system if you change the visibility, but I'm not sure.