Posted per request of ProcyonLotor.
User Dr_Klein_Mengle has been doing some very questionable activities, to put it lightly.
First, they added Columbine references to the Log of Anomalous Objects Volume 2.
They also have an Ideas thread that ties in Nazis: http://www.scp-wiki.net/forum/t-13240131/the-pine-jewelry-box-scp-concept#post-4594503
In addition, they have a sandbox draft that involves a test that turns an entire family Caucasian: http://scp-sandbox-3.wikidot.com/dr-klien-mengle
Finally, it was brought to attention that their name may be a reference to Josef Mengele, a notorious Nazi who performed experiments in Auschwitz.