These are mostly TL:DR and not tailored specifically to online communities, but are mainly valuable for their overviews

DARVO

"DARVO stands for "Deny, Attack, and Reverse Victim and Offender." The perpetrator or offender may Deny the behavior, Attack the individual doing the confronting, and Reverse the roles of Victim and Offender such that the perpetrator assumes the victim role and turns the true victim -- or the whistle blower -- into an alleged offender. This occurs, for instance, when an actually guilty perpetrator assumes the role of "falsely accused" and attacks the accuser's credibility or even blames the accuser of being the perpetrator of a false accusation."

http://dynamic.uoregon.edu/jjf/defineDARVO.html

Institutional Betrayal

"The term "Institutional Betrayal" refers to wrongdoings perpetrated by an institution upon individuals dependent on that institution, including failure to prevent or respond supportively to wrongdoings by individual"..."Victims, perpetrators, and witnesses may display betrayal blindness in order to preserve relationships, institutions, and social systems upon which they depend."

http://dynamic.uoregon.edu/jjf/institutionalbetrayal/index.html

Tactics against sexual harassment: the role of backfire

"...if an action is perceived as unjust and information about it is communicated to receptive audiences, it has the capacity to cause outrage and consequently backfire on the perpetrator. Perpetrators regularly use five types of tactics to inhibit outrage: (1) cover-up of the action; (2) devaluation of the target; (3) reinterpretation of the events; (4) use of official channels to give the appearance of justice; and (5) intimidation and bribery of targets, witnesses and others"

https://www.uow.edu.au/~bmartin/pubs/06jiws.html

"A button to report harassment"