Board Thread:Warhammer 40k General Discussion/@comment-202.67.108.41-20140425072251/@comment-8881468-20150904151019

the inquisition and grey knights kill off complete regiments of imperial guard  and the inquisition has in at least 2 instances attacked loyal chapters of the adeptus atastartes (space wolves and celestial lions)

also: even the astartes involved might simply spare their chapter the shame of taint by taking a warrior's voyage and other forms of penance...