If you download copyrighted material, your ISP might start scolding you by sending you emails, redirecting file sharing websites to education ones and even reduce your download speeds for days at a time. But that seems to be the extent of what will happen. No personal information is to be sent to copyright holders which would mean no lawsuits for sharing copyright material should ever happen.
Source: http://www.theverge.com/2013/2/25/4026194/infamous-six-strike-anti-piracy-program-barks-harder-than-it-bites
Five major internet service providers have signed onto a private sector effort to punish users for downloading copyrighted materials. Advocates say the new Copyright Alert System gives the entertainment industry a new tool to combat piracy, while opponents say it's a hassle for users that won't work to stop illegal downloading. The effort has been underway since 2011 but after suffering delays and missing its scheduled launch in November, it is finally being introduced today.
The Copyright Alert System, also known as the "six strike" system, is a cooperation between ISPs and copyright owners such as movie studios and record companies. The conceit is that the system is just "informing" users that they are illegally trafficking content. "When people share digital files, they can violate copyright law often without being aware that they're doing so," says the narrator of a video produced by the Center for Copyright Information, the group administering the new program.
The participating ISPs are juggernauts Verizon, Comcast, AT&T, Cablevision, and Time Warner, meaning most Americans will be affected by the new program.