Any original work fixed in a tangible medium (including a computer file) is protected by federal copyright law upon creation. Most works may be assumed to be protected by federal copyright law.

Downloading works w/o authority of copyright owner is an infringement of owner's exclusive rights of reproduction/distribution. 

Infringement of copyrighted work may be liable for statutory damages up to $30,000 for each work infringed.

If willful infringement is proven, amount may be increased up to $150,000 for each work. Infringer may also be liable for attorney's fees incurred by copyright owner.

Source:
http://www.copyright.g ov/help/faq/faq-fairuse.html