Six-Strike Copyright Law Now in Effect

There is a new law in the US that relates to filesharing of copyrighted materials, like music, over Internet connections. I'm not sure how this law will affect businesses in the US, but it's something that hostels might want to keep an eye on:
The ‘six strike’ Copyright Alert System is now in place: Here’s what you need to know

At the moment the ISPs are using a six strike system, where the warnings get progressively more serious. I would be really surprised if the punishments didn't become more severe in the future though.

In the words of the Center, “[s]ubscribers are responsible for making sure their Internet account is not used for copyright infringement.” Thus, if your Internet connection is used by your sister’s husband’s dog to download Kanye when you are on vacation and they are house sitting, too bad. It’s still on you.

Here is another article about it:
Internet providers launch controversial Copyright Alert System, promise 'education' over lawsuits

The document purported to be from AT&T says customers will receive email alerts at first. After the fourth and fifth alert, "certain websites" will redirect to "an educational page" and customers will be required to complete a short tutorial before they can access those sites again. After fifth infraction, the document warns, the content owner could sue and force AT&T to turn over the customer's information.

Have any hostels had legal problems with filesharing in the past?

Scotch Argus mentioned a way to block filesharing with opendns.