Multiple games all day on Sunday
Nationally broadcast Sunday Night Football on NBC
Your home team's Monday Night Football appearance
10 Thursday Night Football games on CBS and NBC (and if your home team is playing one of the few TNF games that NFL Network has sole rights to, it will be simulcast on a local affiliate)
Pop-ups—Be prepared to get bombarded with a shitload of pop-ups. However, sometimes ad block will take care of this.
Malware—It's easy to get tricked into downloading something from one of these sites that will really screw up your computer.
Poor quality—Often, pirated streams are pretty low quality. However, every now and then you'll get lucky and find an HD stream.
Connection issues—It's not uncommon for pirated streams to drop out midway, leaving you scrambling to find another to finish your game.
It isn't exactly legal—The word "pirated" entails you're watching something unsanctioned. While you probably won't get in trouble, you never truly know.
NBC—Chicago, Dallas, Hartford, Los Angeles, Miami, New York, Philadelphia, San Francisco, San Diego and Washington, D.C.
FOX— Atlanta, Austin, Charlotte N.C., Chicago, Dallas, Detroit, Gainesville, Fla., Houston, Los Angeles, Minneapolis, New York, Orlando, Philadelphia, Pa., Phoenix, San Francisco, Tampa, Fla. and Washington D.C.
CBS—Austin, Baltimore, Boston, Charlotte, Chicago, Cincinnati, Cleveland, Dallas, Denver, Detroit, Grand Rapids, Harrisburg, Los Angeles, Miami, Minneapolis, New York, Philadelphia. Pittsburgh, Sacramento, Salt Lake City, San Diego, San Francisco, and West Palm Beach.
FOX—Atlanta, Austin, Charlotte, Chicago, Dallas, Detroit, Gainesville, Houston, Los Angeles, Miami, Minneapolis, New York, Orlando, Philadelphia, Phoenix, San Francisco, Tampa, and Washington D.C.
NBC—Chicago, Dallas, Detroit, Hartford/New Haven, Houston, Los Angeles, Miami, New York, Philadelphia, San Diego, San Francisco, and Washington D.C.