I just finished writing a rather long post at Threadwatch about the legality of linking. If you're too lazy to read my rather encyclopedic rant, here is a two-point summary:
A hyperlink is basically a reference. A reference, whether in your kid's term paper or on your homepage, is (in and of itself) legal.Any reference, including a hyperlink, is bound by 'normal' laws which govern speech--e.g., you can't slander someone, you can't steal someone's content, etc.
For a concise breakdown of what the average webmaster needs to know, I suggest Linking Legalities...What You Need to Know by Eric Ward.
What you need to know:
ResponderEliminarIF YOU TELL PEOPLE THEY CAN ONLY LINK TO YOU A CERTAIN WAY YOU ARE A MORON.
You can call me a moron all day long as long as you link to me without nofollow :)