A UK law under consideration and much reviled by privacy advocates would make independent Wi-Fi hotspots legally indefensible: The Digital Economy Bill is a particularly odious piece of legislation that attempts to enforce copyright by requiring ISPs to keep records and disconnect customers who engage in such acts.
This puts the government in the business of taking people off the Internet by enforcing actions for what would otherwise be civil violations, previously needing to be proved in court. Now, something approximating an assertion and a few letters could cause an ISP that doesn't respond appropriately to face huge fines and other troubles. A similar law in France was initially struck down as unconstitutional, but was modified lightly before being approved.
The reason for these laws is to keep media industries from engaging in publicity-adverse lawsuits against individuals, such as those the RIAA (Recording Industry Association of America) led against college students, children, and dead people before sputtering out and moving to this approach.
The not-quite-unintentional consequence of the UK law would, according to advice provided by an arm of the government, put undue burden on hotspots, libraries, and academic institutions. The law requires that most parties be either subscribers (end users) or ISPs; ISPs primarily provide access, and subscribers use it, although there are some fine points. In either case, copyright holders can notify ISPs of violations who are required to notify subscribers. After a small number of violations, the subscriber can be disconnected from any Internet service for some period of time.
If someone downloads an allegedly pirated video over a library, university, or hotspot could force that institution off line if it failed to meet specific notification terms; it's unclear how a hotspot could restrict a banned user without imposing high bars for access, whether free or fee. Larger operations could have login and credit-card verification requirements--used mostly as a way to block people instead of allow them.
Danny O'Brien of the Electronic Frontier Foundation previously raised this concern on 2 December 2009 in a post to the EFF's site: "The repeated demand by the entertainment industry that intermediaries should police their networks has been expanded by the bill to include the subscribers on the edge of the network. If you're not an ISP, but other people use your network to get their net access — if you run an open Wi-Fi spot, for instance, like the British Library — you'll now be vulnerable to being terminated or constrained by the actions of those users."
None of these efforts, of course, deters privacy. As Cory Doctorow, a UK resident and editor of BoingBoing, wrote about this issue:
"The Digital Economy Bill is being sold to us on the grounds that copyright infringement harms the British economy because of the importance of our entertainment industry. But while the measures in the DEB won't stop copyright infringement (copying isn't going to slow down -- as computers and the technology they enable gets cheaper and more widely distributed, copying will continue to speed up, just as it has done since the dawn of the computer industry), they will harm British business and British families, by making the Internet generally less useful and more difficult and more expensive for honest people to use."
In the US, we don't have such a law underway--as far as I'm aware--but media firms have struck deals with some ISPs (and some ISPs have refused) to engage in the same sort of behavior without government involvement.