False and unsubstantiated claims
False and unsubstantiated claims appear often on the Wikipedia mailing list and other forums devoted to maintaining a clique in a position of power. Power grabs are enabled by the tolerance of such claims without any means or standards to examine them, e.g. putting them in TIPAESA form, and restricting or preventing anyone from deleting or modifying them until they are answered to.
Some large public wikis have a single GodKing to declare what constitute false or unsubstantiated. This person is obviously in a conflict of interest regarding such claims made about his own utterances or claims. Accordingly, corruption, e.g. Wikimedia corruption, is the only possible result of failing to have a single pipeline to resolve claims or issues that does not involve the person or people who are actually talked about.
The problem with tolerating unlimited claims is that it exposes one to:
use of this phrase to intimidate
It is also common to label fully substantiated and easily documented claims as "false" or "unsubstantiated" as a means of intimidating those who make them. This tactic is seen for instance on both sides of troll-sysop struggle and has marked the GFDL corpus debate to a remarkable degree: reducing the entire project to tabloid journalism at best, libel pit at worst, and rendering Wikipedia useless as reference for journalistic purposes.