There is absolutely no doubt in my mind that people who use apostrophes incorrectly is just taking the proverbial biscuit.The Apostrophe Vigilante had better watch out for the Subject-Verb Agreement Vigilante.
The plucky punctuators fighting against apostrophe catastrophes (The Independent)
[Vigilantes are tiresome.]
July 10, 2013: A comment on this post points out that the Twitter account @apostrophelaw is unrelated to the source of the above quotation. The Independent appears to have conflated the various vigilantes.