Libel against Wikimedia
While libel against Wikimedia is probably legally impossible (due to Florida law, see below), claims that such lawsuits will be pursued (using donated and public money presumably - what other money does Wikimedia have?) constitute libel chill very often on the Wikipedia mailing list. With no real prospect of gaining damages for the Wikimedia Foundation there is no way to interpret such a use of funds as anything but Wikimedia corruption, should it occur, advancing the interests of officers not that of the foundation itself.
Those making true statements about organizations with very poor reputations are libel-proof under Florida law. In a 1999 case involving a convicted criminal seeking parole, his "reputation before the article was so poor, and that the undisputedly true statements in the article were so harmful, that he could not be further injured by supposedly false statements about his criminal past." - 
Since Wikimedia often engages in criminal libel (usually in the context of trying to expose its enemies) and authorizes various forms of confiscation of property (donated works of GFDL contributors) with no legal basis for claiming ownership or control, it would seem quite difficult to be guilty of libel for simply saying this is so. As a great many people have done.