A Suethor is, as the name suggests, an author who writes a story in which the protagonist is a Mary Sue. This person may do it knowingly, unknowingly, or even unwillingly; many times an author seeks not to write a Sue, but doesn't succeed.
Misinformation and lack of analysis are closely linked to the continued creation of many Sues. The term Mary Sue may not have been adequately defined to the Suethor, the Suethor might be young and unaware of the inconsistency in their story, or they may not yet have the writing experience required to assess their own work objectively or critically. There are, however, some Suethors who just don't care or even see writing a Sue as a good thing (there's at least one such community out there).
Because writing a Mary Sue is an accusation of poor skill and sometimes interpreted as an attack on an author him/herself, some Suethors react very badly to any form of criticism, even concrit. Usually the worst of it consists of "You're meen!!!11!!!one!!!1", the use of chatspeak, and/or various excuses. This, too can be connected to their products: a person who treasures a character so highly as to give them all of the superpowers and the prettiest mate might also be very emotionally attached to that character... and react negatively when that character is criticized.
Many writers start out as Suethors, but most grow out of it, often around their late teens. This can even be observed in published fiction: Amelia Atwater-Rhodes, Flavia Bujor, J. Fenimore Cooper, and Christopher Paolini all have protagonists who are Mary Sues. Eragon and Natty Bumppo are two of the most blatant Mary Sues in existence, even counting the many Sues in fanfiction.
Suethors are people too, and we respect that. The PPC does not use this term as an insult. Any Suethor can come to us, at any time, and ask for advice. The PPC offers free and open beta-reading and review for any fanfic a person wants to send our way: even badfic. The fact that this doesn't happen very often is really a shame.
Suethors, The PPC, and Mission Conduct
The PPC does not go after Suethors. The PPC's business is with their products: the badfic that they write. Badfic is not an accurate measure of a real person. Someone who writes even the creepiest, most unapologetic badfic has the potential to improve; many PPC writers have gone through their Sue-writing phases and come out the other side. Above all else, a badfic is a temporary reflection of a Suethor's skills and mindset, not a permanent one... and it is not fair to judge a person forever based on a bad bit of fanfiction.
This does not stop their products from being bad. Badfic is to be sporked. Suethors are to be left alone. Questioning their choices in a mission is all right as long as no nasty insults or other un-PPC-like things are flung. Going after or assassinating them is right out: since they are real people, that would constitute murder; the only PPC agents with any authorisation to deal with Suethors were those who worked in the former Department of Author Correspondence, which was intended to help them improve as writers. Attacking Suethors would also further blur the line between reality and fiction in the PPC, which has taken quite enough abuse as it is.