Protesters were dispersed with tear gas on Thursday, the first day of the two-day G-20 summit.
A self-described New York City anarchist has been accused of tweeting the location of police officers to protesters trying to evade them during the Group of 20 economic summit in Pittsburgh, Penn.
Pennsylvania State Police arrested Elliot Madison alleging he used Twitter to direct the movement of protesters and inform them about law enforcement actions at last month's summit.
The New York Post reported the arrest in Saturday editions.
Court papers filed by Madison's attorney say FBI agents executed a search warrant at the 41-year-old's Queens home on Thursday. They seized computers, political writings and anarchist literature.
Madison faces charges including hindering prosecution.
His attorney didn't immediately return a call requesting comment Saturday afternoon.
Copyright Associated Press