A pair of German computer hackers were apprehended by authorities after allegedly gaining access to the personal computers of over 50 pop stars – including Justin Timberlake and Lady GaGa.

Exactly what and how much information was stolen is unknown, but German police say that by using Trojan Viruses, the two obtained unreleased music, credit card information, e-mails, and photographs. The grand scheme was to steal the material and then blackmail the artists in order not to release it, or to sell the music outright – which did happen in a couple of cases. Prosecutors say the blackmail attempt happened in at least one instance – when the computer gurus obtained x-rated photos of singer Ke$ha. However, no money exchanged hands.

It is believed that at least a couple of artists were forced to push up the release date of their forthcoming album due to the hackers’ efforts.

The Telegraph – a publication in the U.K. – also reports that federal agents were tipped off by none other than Kelly Clarkson, who first learned about unreleased demos leaking on to the Internet from her fans. The hackers, aged 17 and 23, have yet to be formally charged.