An Australian Appeal court has upheld a ruling from last year that linking to copyrighted content contravenes Australia’s copyright laws. The site in question was mp3s4free.net which was raided by MIPA in 2004 which then led to the lawsuit brought by the major record labels.
The question of link sites is an interesting one and legal decision vary from country to country. It is one of the reasons why Bit Torrent indexes are hard to tackle legally.
Find some discussion of US rulings on linking here including some of the cases which never reached court.