"In a way, it's kind of a hobby seeing how good the dissertations are in question of authenticity," Debora Weber-Wulff, a professor of media and computing at the HTW science university in Berlin, told Reuters on Tuesday.

But the anonymity of the Internet activists has raised questions about their ethics, especially if the allegations prove to be unfounded, plagiarism expert Volker Rieble told Reuters. "On the one hand it's good that people are paying attention to this," said Rieble, a law professor at Ludwig-Maximilians University in Munich.