You must have the rights to any images, video clips, or music files you upload into your Animoto video.
Animoto absolutely respects the rights of copyright holders for images and music. Our policy is to respond to any notices of alleged infringement that comply with the Digital Millennium Copyright Act (DMCA), which may include removing the content.
Animoto reserves the right to terminate your account and video creations in accordance with our Terms of Service.
If you're curious about music licensing, you may want to check out HowStuffWorks' article on "How Music Licensing Works".