All Animoto videos are private unless you share your video's play page link with others and/or post it elsewhere.
Videos can only be downloaded when logged into the account where they were created. That means that nobody can get access to a downloadable copy of your video unless you share the file or your account login with them.
When you share a link to your video, the viewer is only able to stream a copy. The end of the play page link contains a random selection of characters, which is hidden from search engines and can't be guessed. That means no one can stumble across, search for, or access your video without your permission.
Since your viewers are only able to stream a copy of your video via the play page link, all links and embeds will also be disabled once you delete the video from your Animoto account. Videos links and embeds that were created in accounts that are currently archived will also not be accessible while the account is in archive.
Users on the Professional or Professional Plus plans can also hide the branding from their shared links so your viewers are taken to a totally unbranded playback page. If you remove the branding from your video, your viewers will have no way of knowing where the video was created or where it's hosted.
For more information, check out, Share your video without Animoto branding