Where to begin? How about with the big free speech victory in CDT v. Pappert?
The decision is a real victory for free speech against overbroad government action, made even more notable by the fact that the court resisted the temptation to invoke the talismanic evil of child pornography as a justification for censorship. You can read the opinion, or CDT's concise summary.
The kernel of it is Pennsylvania's Internet Child Pornography Act, which empowered the Pennsylvania AG to seek a court order requiring ISPs with customers in Pennsylvania to "remove or disable items residing on or accessible through" the ISP's service upon showing of probable cause that the material in question is child pornography. Not content with that authority, though, the Pennsylvania AG sent a series of "notice" letters to ISPs, not-so-subtly pressuring them to "voluntarily" disable access to the material with no court proceeding whatsoever. Most did -- and they did so through IP-address blocking. In an era of IP-sharing, these secret letters had the effect of blocking over a million web sites and other resources.
The court (properly) found both the underlying law and the AG's acts unconstitutional. A real victory for free speech . . . but another highlight of just how hard law enforcement's job is becoming. Could Pennsylvania lawfully order ISPs to install URL-based filtering, to be activated (only) upon a court order? It might not be effective, but it probably wouldn't be totally ineffective and it might be the next step.