Copyright infringement:

In some countries, the personal copying exemption explicitly requires that the content being copied was obtained legitimately – i.e., from authorized sources, not file-sharing networks. Other countries, such as the Netherlands, make no such distinction; the exemption there had been assumed, even by the government, to apply to any such copying, even from file-sharing networks. However, in April 2014, the Court of Justice of the European Union ruled that "national legislation which makes no distinction between private copies made from lawful sources and those made from counterfeited or pirated sources cannot be tolerated." Thus, in the Netherlands, for example, downloading from file-sharing networks is no longer legal.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". What does the personal copying exemption explicitly not need?
unanswerable