"The man, Elliot Madison, 41, a social worker who has described himself as an anarchist, had been arrested in Pittsburgh on Sept. 24 and charged with hindering apprehension or prosecution, criminal use of a communication facility and possession of instruments of crime. The Pennsylvania State Police said he was found in a hotel room with computers and police scanners while using the social-networking site Twitter<http://topics.nytimes.com/top/news/business/companies/twitter/index.html?inline=nyt-org>to spread information about police movements. He has denied wrongdoing."