Wikipedia:Witch hunt
A witch hunt is an action taken by a Wikipedia editor to find fault or violations in another editor when it is not already obvious that such has occurred. It is often a lack of assumption of good faith and should generally be avoided.
Some editors may be concerned that another's activities may not conform to Wikipedia guidelines, and may become so obsessed with that possibility that they go to the extremes of studying the edit histories of others very deeply as if they were detectives conducting a homicide investigation. One who engages in this type of behavior misses the point as to what Wikipedia is really all about.
The purpose of Wikipedia is to provide the world with an encyclopedia from which anyone can obtain free knowledge. It is a place for teamwork, where the goal is for everyone to work together for the best possible results. It is not a place to fight for superiority over others, to be a bully, or to seek to accuse others of things.
So you are considering getting another editor "in trouble" for something. Be aware, action that is taken against editors is not punitive. The only purpose of blocking, banning, and other sanctions is to protect the encyclopedia from harm. It is not to "punish" the offender for their wrongdoing. So if you decide to engage in some witch hunt, just be aware that even if perhaps an editor did violate some policy, what is taking place against them is not a prosecution or trial. Any discussions being held are only for the goal of improving the quality of the encyclopedia. So if an editor maybe did break some rule, but has mostly spent their time doing good things, do you really want to stand in their way of their worthwhile contributions and make them unable to edit for a period of time?
Examples of witch hunts
The following are some examples of witch hunts.
Deletion of articles
There is an article up for deletion. Everyone agrees it is a "bad" article. A witch hunt would be to look at the creator's edit history to find other articles the creator may have created, and to see if they should be proposed for deletion as well. However, if an editor exhibits a long-term pattern of creating bad pages – especially if they keep clearly violating a policy such as WP:Copyright, WP:Biographies of living persons, or WP:Paid contribution disclosure – then the community might undertake a review of the editor's page creations and other major contributions. We even have some formal processes for this, such as WP:Contributor copyright investigations.
Sock puppetry
It is suspected that two accounts may be operated by the same person or by two people who know each other. Both accounts have a history of making good-faith contributions, and nothing obviously untoward is happening with either of them. A witch hunt would be to examine the contribution histories of both accounts and to look for signs to see if sock puppetry could be occurring.