According to Douglas Wagner in The Arizona Gazette, two self-anointed "grammar vigilantes" who toured the nation removing typos from public signs have been banned from national parks after vandalizing a historic marker at the Grand Canyon. Jeff Michael Deck, 28, of Somerville, Mass., and Benjamin Douglas Herson, 28, of Virginia Beach, Va., pleaded guilty in U.S. District Court in Flagstaff after damaging a rare, hand-painted sign in Grand Canyon National Park. They were sentenced to a year's probation, during which they cannot enter any national park, and were ordered to pay restitution. According to court records, Deck and Herson toured the United States from March to May, wiping out errors on government and private signs. On March 28, while at Desert View Watchtower on the South Rim, they used a white-out product and a permanent marker to deface a sign painted more than 60 years ago by artist Mary Colter. The sign, a National Historic Landmark, was considered unique and irreplaceable, according to Sandy Raynor, a spokeswoman for the U.S. Attorney's Office in Phoenix. Read more. Listen to a story about their project, the Typo Eradication Advancement League, on NPR.