Starting tomorrow, major ISPs will begin enacting the 6 strikes rule thanks to our friends at the RIAA and MPAA.
If you are found to be illegitimately sharing or downloading content, the 6 steps will begin:
1-4) The first four infractions will result in an alert or notification. These alerts will continue to get more and more invasive possibly redirecting you to a landing page to click through several steps to acknowledge the rules.
5 and 6) The ISP will begin mitigation efforts which may include reducing your Internet speeds or permanently redirecting you to a page indicating you must call the ISP to discuss the matter before they will turn it back on.
This is purely up to the ISPs but most don't include any plans to disconnect the users as they don't want to lose customers or have to deal with lawsuits. However, the plan requires that the ISP must have some form of automated system to know how many times each customer has been notified.