Two state senate candidates in San Francisco have agreed to face off in ''Pokemon Go,'' the free game app that has captivated the country. San Francisco Supervisor Jane Kim issued the challenge via a playful tweet on Tuesday: ''OK (at)Scott-Wiener-one last challenge. This is it. Maybe this will get a yes! Will you (hash)PokemonGo?'' Scott Wiener, also a San Francisco supervisor, agreed with his own tweet : ''Finally, a real challenge (at)JaneKim! Game on!'' The San Francisco Examiner reported the exchange Wednesday. Earlier this month, Wiener asked Kim to sign a pledge to stop demanding gimmicky pledges; this was after she asked his campaign to pledge to a positive campaign, including not using her name. ''Pokemon Go'' asks players to wander real neighborhoods as they hunt for the animated monsters. 5:55 p.m. University of Maryland campus police say three of four recent robbery victims on the College Park campus had been playing Pokemon Go. Three of the victims of the Tuesday night robberies were students. Police say the suspect showed a handgun in two of the incidents. No one was injured. Players are being urged to pay attention to their surroundings after reports around the country of robberies involving people distracted by the game. 5:35 p.m. People playing Pokemon Go accidentally interfered with a search for a mysterious man who'd fled from a Lincoln, Nebraska convenience store where a clerk was killed last week. Police say a store security guard noticed the man around 2 a.m. Wednesday. He was dressed in camouflage clothing and wearing a hood, gloves, sunglasses and a bandanna over his face. The guard asked the man to remove his bandanna, but he ran off instead. A police dog taken to the scene to track the man got distracted by the scents of some people engrossed in the popular new smartphone game nearby. Police say they don't think the man sought is connected to the slaying of store employee Robert Hanna. 5:20 p.m. Four suspects have been arrested after a man told police in Auburn, Alabama that he was robbed at gunpoint while he was playing Pokemon Go. Auburn police said in a news release that the man was playing the game outside of a vacant building early Wednesday when he was approached by four men who attacked him and robbed him before fleeing in a vehicle. Authorities found the suspects, who were charged with first-degree robbery and third-degree assault, and recovered the victim's stolen property. 5 p.m. A woman in western Pennsylvania says her 15-year-old daughter was hit by a car while playing the popular new ''Pokemon Go'' game on her smartphone. Tracy Nolan tells WPXI-TV the game took her daughter across a busy highway Tuesday during the evening rush. She remains in the hospital Wednesday with an injured collarbone and foot, as well as cuts and bruises. The car's driver stopped and held her daughter's hand until emergency responders arrived. 4:35 p.m. So what is Pokemon Go ? It's a free game app that you can download for your iOS or Android smartphone. The game asks players to wander their real-world neighborhoods on the hunt for the animated monsters made famous years ago by cartoons, video games and trading cards. Players build their collections, make their Pokemon more powerful and battle other trainers in gyms. Set up is relatively quick. Fans like how it takes gaming into the streets and gets people walking around outside. But the game has prompted privacy concerns, worries about walking into unsafe situations and trespassing on private property. 4:35 p.m. It's not easy for businesses to opt out of Pokemon Go, nor is it automatic. This form is on Niantic's support page. But it is by no means a guarantee, and it's unclear how quickly, if at all, Niantic would respond given the overwhelming popularity of its game. Using the form, you can ask Niantic to remove a ''Pokestop,'' where gamers can pick up special items, or ''gym,'' where they can battle and gain power. You must provide the feature's name, address and the reason why you want it removed. A drop-down menu forces you to pick a reason to get rid of a Pokestop or gym, but these may not match why a church, business or museum wants it gone. The choices include if the location is dangerous, on private property or if it does not exist. 3:40 p.m. The Pokemon Go craze in the U.S. has people wandering into yards, driveways, cemeteries and even an off-limits police parking lot in search of cartoon monsters. Authorities and others are warning trespassers they could get arrested or worse - especially if they cross paths with an armed property owner. Since the release of the smartphone game last week, police have gotten a flurry of calls from residents about possible burglars or other strangers in their neighborhood. So far, few tickets have been issued, and there have been no reports of arrests or assaults on trespassers playing the game.