No legal threats is a policy of some Wikimedia wikis, such as the English Wikipedia.
Perceived legal threats
Sometimes comments are understood as legal threats, even if the comments are not intended in that fashion. For example, if a user repeatedly asserts that another editor's comments are "defamatory" or "libelous", that editor might interpret this as a threat to sue for defamation, even if this is not intended. To avoid this frequent misunderstanding, some users use less charged wording (such as “That statement about me is not true and I hope it will be corrected for the following reasons...”) to avoid the perception that the user is threatening legal action for defamation. It has been argued that rather than blocking immediately, administrators should seek to clarify the user's meaning and make sure that a mere misunderstanding is not involved.
There have also been cases in which a promise not to pursue legal action was interpreted to be a legal threat. E.g., "I . . . request that discussion of the necessity of a complete ban be reopened . . . In the interests of making it easier for the ArbCom to discuss the matter openly (rather than in non-transparent channels such as the ArbCom listserv), I also agree to hold Wikimedia and all participants in such discussions harmless for any statements they publicly make with regard to me. I agree not to sue for libel for anything anyone writes about me . . . I'll sign a waiver if you want." Although intended to allay concerns about possible litigation, this statement could actually be misconstrued as implying that the user's refraining from suing is contingent upon the ArbCom's agreeing to his request that the discussion be reopened. Thus, it could be viewed as a veiled ultimatum threatening to sue if the ArbCom does not reopen the discussion.