While the RIAA has been making headway in the United States by suing anonymous alleged file sharers with just an IP address and obtaining their names and addresses from the Internet service providers, things could prove more difficult in Europe if a recent court recommendation holds up.
An advisor for the European Court of Justice has stated that Spain's Telefonica is not required to reveal the identity of file swappers so Spanish music association Promusicae could take legal action against them. Telefonica argued that it should only have to disclose personal information for a criminal prosecution, not a civil action. The advisor's opinion will be taken into consideration by the judges, which typically follow such recommendations.
News source: BetaNews