A recent judgment from the Court of Justice of the European Union (Case C-435/12 ACI Adam BV and Others) ruled that private copying limitations cannot permit downloads from unlawful sources.
João Pedro Quintais & Alexander de Leeuw, have a detailed peice on the case on the Kluwer Copyright Blog.
Here is an excerpt from the ruling:
“national legislation which makes no distinction between private copies made from lawful sources and those made from counterfeited or pirated sources cannot be tolerated. … First, to accept that such reproductions may be made from an unlawful source would encourage the circulation of counterfeited or pirated works, thus inevitably reducing the volume of sales or of other lawful transactions relating to the protected works, with the result that a normal exploitation of those works would be adversely affected. Secondly, the application of such national legislation may, having regard to the finding made in paragraph 31 of the present judgment, unreasonably prejudice copyright holders.”