If you want to download as videos itself, you can use other free tools like Free Youtube Download to download all videos with a single click. Please be careful while installing this tool as it optionally installs a browser toolbar and modifies search preferences. So please make sure you read and uncheck the optional checkboxes while installing to avoid surprises in your browser. 

Backup software: We run each program through the various types of backups it’s capable of. This is largely to test reliability and hardware compatibility, but we time two: an approximately 115GB system image (two partitions), and a roughly 50GB image created from a set of smaller files and folders. We then mount the images and test their integrity via the program’s restore functions. We also test the USB boot drives created by the programs.
Most services encrypt your files with strong systems such as AES 256 before sending them up to the servers over an encrypted connection. The majority of products we tested also offer a private encryption key option. If you choose to manage your own encryption keys (basically the "key" that decrypts your backup), know that it is your responsibility to remember it. The online backup service itself will not be able to help you reset the password if you forget it. On the flip side, this means that no one (including employees of the backup service and law enforcement officials) other than you can unlock your backups. This is ideal from a privacy and security standpoint. Use a password manager to keep track of your private encryption key if you think you will forget it.