The answer is not quite what I expected. Over 50% of the editions from just seventeen authors are unsigned. Here's the list:
|Gebhard <Köln, Erzbischof>||20||27||74.1%|
|Elisabeth <I., England, Königin>||10||14||71.4%|
|Oranje-Nassau, Willem van||9||13||69.2%|
|Werner, Johann Sigismund||10||15||66.7%|
|Karl <Frankreich, König, VIIII.>||23||36||63.9%|
|Friedrich <Würzburg, Bischof>||7||12||58.3%|
|Johann Wilhelm <Sachsen-Weimar, Herzog>||19||34||55.9%|
|Ferdinand <I., Römisch-Deutsches Reich, Kaiser>; Moritz <Sachsen, Kurfürst>||10||18||55.6%|
|Heinrich <IV., Frankreich, König>||25||45||55.6%|
|Maximilian <II., Römisch-Deutsches Reich, Kaiser>||31||56||55.4%|
|Condé, Louis de <1530-1569>||8||15||53.3%|
|Heinrich <II., Frankreich, König>||8||15||53.3%|
It's not too surprising, perhaps, to find an apocalyptic calculator (Poyssel) and another prophetic tract (Severus) on this list. One example of fool literature (Stengler) and Rollenhagen (principally his Postreuter and Hinkender Bote) are a bit more surprising. Johann Sigismund Werner makes sense for his religious views, although Caspar Schwenckfeld comes in at only 31%. Jacobus Francus, a pseudonym in any case, deals with recent and perhaps politically sensitive history and might be considered proto-journalism.
But the real surprise are all the writings attributed to royalty, including several foreign monarchs. I suspect that what proved controversial was appropriating their edicts or other writings and publishing them as polemic of one kind or another, which might be a politically sensitive undertaking of the kind that most printers preferred to keep their names off of, even as they were making money off of them.
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